Yes, he certainly isn't the sharpest tool in the box is he?

1. I have had cats and computers for years. At worst you get a popup menu or a system freeze.

2. The guy says this stuff "just appeared" after the cat had jumped on his keyboard..............so why didn't he "just delete it" then, as he obviously knew it was there?

A much more plausible defence would be dodgy P2P sites and warez, but I think that the Sheriff has a lot more evidence that just the images.