He may only have provided access, but I presume he had full knowledge of what was intended? If he knew what was going on, then in my opinion, he is equally responsible.
I suspect Willams' sentence may have something to do with his publishing child pornographic images...
Now, I hate to be the antagonist here, but...
"viewed images of child pornography since he was only 11 or 12"
...does that still class as child porn, or just porn? - Regardless, he's no long 12.
Re: Did you see them?
> how do you know they were child abuse images instead of just regular child porn?
Because regardless of whether acquiring these images involved physical or mental abuse, involvement in it is pure abuse of power & trust.
> I find it very hard to believe that this young well spoken guy would be interested in this stuff
Again, being the antagonist, I doubt people have much control over their attractions. Whether they choose to pursue them or not, is a different matter.