Well, it's hard to be specific since nobody ever mentions which patents they're talking about. But I would assume that somebody at AMD has the skills to determine whether Nvidia uses the "good matrix" technique, or whatever it is people are assuming AMD patented that Nvidia is trying to hide.

In court, there's a big difference between your assumption vs. published code.

Drivers are published code, freely available. If the driver does something, and you can't find an expert witness to testify it does what it does, maybe it doesn't do what you think?

Reading assembly with no comments is a different skill than reading C or C++, especially since it's not always clear what's an instruction and what's data, but it's still reading code, and there are tools to help you trace through it. And most of the drivers aren't writing code like it's a 64k demo (where the code is the data, and the data is the code, and they both modify each other)