That's a bold statement - I don't know his full history or all the facts of his case, but what you're implying is that someone's past actions and convictions are all that's needed to asses their present guilt.
Did it ever occur to you that maybe he was innocent and maybe he knew everyone would think like you? It doesn't take much to realize that this way of thinking quickly leads to a conviction regardless of the facts.
There are people who will try to root your computer, and who prefer to do their bad stuff from someone else's computer so that the heat won't come back to them. If you hang around with the wrong crowd and don't know what you're doing well enough, the odds of this happening go up. Suppose that this happened to him the first time around, and the forensics were done poorly, so he took the fall for someone else's crime. Then it starts happening again, and he knows he won't be believed because he wasn't before.
I would rate this scenario as unlikely, but not impossible. However plausible enough that I don't accept the clearly in, "He was clearly someone..."