It's also a strict liability crime, so intent doesn't matter. The evidence can't be viewed except by very few people approved by the justice department, so CP might just be pictures of a 17th year old that the person didn't even know was underage.
you obviously didn't read the indictment. The claims are not some vague image found in his browser cache, but Gigs of graphic and disturbing content with metadata (i.e. titles) that clearly indicate it as CP.
I realize these claims != guilt, rather that a lot of these comments are arguing how easy it would be to get caught up in existing laws. That's not what's claimed here; if true this guy is a collector.
50+G of encrypted data, specific references to 6yo, 8yo in file names and confirmation by a LEO witness that the videos match the filenames. The videos presumably can be viewed in part (by the judge?) in some sort of closed session if the defence requests it?