Or, how about some other choices? 1. The explanation, even if innocent, would have sounded so lame to (especially) non-computer savvy jurors that it would have made him look even more guilty (your narrative, for instance, might have lots of people snickering and saying, "oh yeah, that's the ticket, it was all innocent, snicker wink nudge..."); 2. he honestly didn't know about the child porn, because it had been downloaded (and when you browse an image, you download it--it's in your cache) by his son in secret.
After seeing some pedophile cases here in Oklahoma, I'm convinced that if he had a bonafide interest in having sex with children, there would have indeed been a mountain of evidence--on his computer, and in hardcopy. Recent cases here have shown LE carting away boxes piled upon boxes of the pictures and magazines, and loading them into the back of trucks the size of regular U-Haul moving trucks. The computers were loaded down with thousands and thousands of not only pictures, but emails with others of like mind. They like to share stories with one another, apparently, along with pictures.
None of this ever appeared with DW. I find that troubling. Under 100 images, most of which had been (apparently) immediately erased--this does not suggest a man who's really sexually interested in children. If the original figure we all saw had been valid--and it wasn't--68,000 child porn images--that would have been more in line with the computer of a pedophile.