How do you protect patents from judicial and expert hindsight?

The Hindsight Glasses gave Merpel the
power to see that all inventions
were obvious

Oh, hindsight...a wonderful thing.  Unless, of course, you are patentee.  A couple of Tuesday evenings ago, when it was still brutally cold in London, Dr Siva Thambisetty, Associate Professor of Law at the LSE, hosted a seminar which was cryptically titled “Inventive Step in the UK and Use of Experts in Patent Litigation”.  Rachel Mumby (Bristows) reports on the event:  

"All that attendees knew before the event was that the intention was to “explore the cognitive burden and mechanics of litigation strategies on inventive step”.  

After a mad dash from the office, several attendees could be found wandering the halls of the LSE searching for the correct room, because all they could find was a room with large numbers of people seemingly doing an exam. In fact, that room was the correct place to be, because the evening started with all participants being handed some papers to read, including a patent litigation scenario and short expert report (prepared by Alan Johnson of Bristows). Participants were then asked to answer a series of online questions, including what they thought the likelihood was of the patent in suit being held to be obvious. Participants were also warned not to confer with their comrades as not everyone had the same information. So, after a certain amount of huffing and puffing about being required to think, participants settled down to the task in hand. 

After the survey had been completed, Dr Thambisetty explained that the survey was part of research being done in relation to hindsight bias and blinding in the assessment of obviousness, for example looking into the probative value of blinding and whether it can affect litigation outcomes. She also introduced Prof Christopher Robertson of the University of Arizona who is leading this study. 

Prof Robertson then took to the floor and gave a fascinating presentation on hindsight bias, noting that over 800 papers have been published on the topic (across many different fields, not just patents). The audience learned that hindsight bias is very much part of human nature. Further, this issue is not restricted to mere mortals, but experts and judges have the same problems (and sometimes worse). It has been psychologically proven that once we know that a particular event has happened (e.g. an invention has been made), the facts which previously pointed away from that event happening become harder to remember. What’s more, there is no strong evidence to suggest that any of us can reliably channel our mind to avoid hindsight bias – we cannot help ourselves. This is why blinding (and particularly double-blinding) is so important in clinical trials and also, for example, police line-ups. 

Next Dominic Adair (Bristows LLP) complained very politely about the steps which, following MedImmune v Novartis, patent litigators take to try to minimise hindsight bias when working with experts. He discussed the great time and cost which is incurred in discussing the CGK and then the prior art, often with multiple prospective experts, before they can be shown the patent and it can be determined whether they will be suitable for that case. In particular, he noted that for a party surprised by receiving an infringement action it is almost impossible to complete this process in the 6 weeks between being sued and needing to file Grounds of Invalidity citing particular pieces of prior art. Further, in some cases experts are needed to assist with assessing a potential infringement, and this work has to be carried out before the other side has cited any prior art. In other cases it may be clear from the outset what the patented technology will be, making the staged approach something of a farce. Indeed, in circumstances where the invention exists in identifying that there is a problem, it can be incredibly difficult to frame the discussion without discussing the shortcomings in the state of the art. What happens if new prior art is cited during the proceedings? Can solicitors and barristers not be trusted to educate experts on the dangers of hindsight bias and seek to avoid this?

Anna Edwards-Stuart (11 South Square) then took up the microphone and provided the alternative view. She reminded the audience that patent law, in particular the concept of the person skilled in the art, is inherently artificial. Experts rarely personify the person skilled in the art and can only test their views against their own experience. This means that without steps, such as sequential unmasking, being taken to try to avoid hindsight bias, the expert becomes vulnerable on cross-examination.

Citing Arnold J’s comments in American Science v Rapiscan, Anna also noted that care still needs to taken with sequential unmasking. Further, bias does not only crop up when documents are read in a particular order, hindsight bias can also arise if experts are instructed to focus on one passage of the prior art to the exclusion of others, or where elements of the CGK are cherry-picked to form a CGK attack. She concluded that the most important thing is that it is made clear in expert evidence how the expert has been instructed, what opinions he/she gave when, and that the basis for any opinions given are carefully explained.

Next came the analysis of the results of the survey. The audience were told that half of the room had read expert reports which made it clear the steps that had been taken by the expert to avoid hindsight bias (for example the order that documents had been read in) and half had not. Interestingly, the results were the opposite of those expected, but this may be down to the small sample size and slightly rushed nature of the exercise. Interestingly, one clear message was that participants thought that blinding is valuable but not practical in patent litigation. 

The evening concluded with comments from Arnold J and Dr. Matthias Zigann (presiding judge of the Munich Regional Court), and also some emailed observations from Birss J (who was unable to attend).

Arnold J noted that the literature is conclusive that experts are no better than lay people at avoiding hindsight bias, and that telling someone to avoid hindsight does not work. He suggested that experts being blinded as to which party is instructing them is one way of avoiding some bias, but that does not avoid hindsight bias. He went on to observe that there is a breadth of literature which shows that linear unblinding, and reaching conclusions at each stage of the process is helpful. However, he stated categorically that this is not compulsory when instructing experts, and accepted that it can be costly and can in certain circumstances be an impossible approach. Having said that, he also observed that in the Courts of England and Wales we place considerable weight on expert evidence, and if we are to continue to do so, we need that evidence to be as high quality as possible, which should make the parties want to ameliorate potential weaknesses such as hindsight bias. (In other words, you don’t have to do it, but on your head be it if you don’t and could reasonably have done so.) 

He also observed that as Judges are not immune to hindsight bias either, it is helpful to know that experts have been instructed linearly. Further, as hindsight bias produces an asymmetric effect, tending to favour the party seeking to invalidate a patent, Judges should lean the other way to try to compensate for this. 

He concluded by picking up on a point raised by Anna Edwards-Stuart, that patent law is grounded in hindsight – it is legally routine for prior art to be selected with hindsight, but this does not mean that nothing should be done about bias when assessing obviousness. 

Although unable to attend, Birss J had already provided some views on the subject (which he knew to be at odds with those of Arnold J). In an email which was read out by Dr Thambisetty, Birss J opined that: 

1. The concept of blinding in patent litigation is fundamentally flawed.
2. The role of experts is to educate the Court, not to come to conclusions on obvious, or be used like an experiment to test whether or not something is obvious. Therefore, blinding of experts is unnecessary.
3. If blinding is to be used, single blinding is not sufficient – to be effective double blinding is required (i.e. legal teams mustn’t know which side they are on). Indeed, in his view lawyers sometimes knowingly or subconsciously lead their experts towards particular conclusions by the nature of the questions they ask.
4. If experts are to be blinded, then judges also need to be blinded and to read documents in a particular order, giving their opinions along the way.
5. Experts are almost always more skilled than the “person skilled in the art” so does analysis also need to be done on how much more skilled they are in order to assess their blinded opinion? 

Dr. Zigann then provided a German viewpoint, which appeared to be that experts, and more particularly party experts, are unnecessary. He argued that experts are not needed to determine obviousness as this is a matter of law. Further, if the only thing the expert contributes is an explanation of the technology, then this can be done by lawyers, or if necessary, with a court appointed expert (court appointed experts have some of the same hindsight bias issues as party experts, but they may not be exposed to other types of bias).

The evening concluded with an acknowledgement of the fact that at least hindsight is not as inherent in the English system as it is at the EPO where hindsight is an inevitable part of identifying the closest prior art, and where the problem to be solved is formulated from that closest prior art.

The broad consensus was that it was a captivating and thought provoking evening. It is clear there is no ideal solution, but those present enjoyed the opportunity to learn a little more about this topic which is so fundamental to the way many cases are run."