Something every new patent practitioner learns is the difference between patentability and infringement. There is a difference between being able to sell a new product and being able to patent a new product. While it might seem like these two questions are related, in reality they are totally separate. That is why when evaluating patentability of a new invention, the claims of the prior art references are essentially irrelevant (they count as disclosure, of course, but their legal scope of coverage for infringement is not a concern to the specific issue of patentability).
Unfortunately, some members of the Supreme Court seem confused about the distinction, as illustrated in their questioning in the recent oral argument for Return Mail. I don’t profess to know anything about the presumption of whether the government is a person, but I do know the difference between the ability to obtain a patent and being sued for infringement. Whether or not claims of a patent are determined to be invalid in an IPR has nothing to do with whether later inventions developed by the petitioner can be patented. This is not so clear to some member of the Court, including Justice Kagan.
Specifically, in trying to determine whether the governments ability to own patents somehow answers the question in Return Mail, Justice Kagan posed the following question (emphasis added):
JUSTICE KAGAN: Right, but I guess what I'm -- I wanted to ask was whether those provisions, the 207(a)(1) that the government can obtain a patent, 207(a)(3), which is that the government can protect its rights to inventions, whether those might also lead you to say that the -- that the -- the -- that the government is a person for means of bringing these challenges, because the idea, I think, would be something like these challenges to the PTO are a means of -- enable the government to innovate and to obtain patents itself. In other words, the government is looking at an area, it says somebody is claiming a patent on this, that's preventing us from inventing, that's preventing us from getting a patent, so we have to kind of clear the field in order to innovate. And that's what these challenges enable the government to do, so that they are a kind of function of 207(a)(1) and 207(a)(3). What would you think of that argument?
This hypothetical is of course wrong. Whether or not a challenged patent is upheld by the PTAB, that patent document is still going to be prior art to the government’s new invention that it is seeking to patent. Nothing is preventing the government from inventing at all, at least nothing that can be solved by attacking the prior art reference as invalid before the PTAB. Rather, the issue is that the government might be liable for infringing if it practices its new invention.
I am not sure it really matters at the end of the day, but it just seems like the basics of patent law should be clear to everyone before trying to decide a particularly narrow and specific issue within patent law.