Well, he was always kind of weak and wary of Joe. Considering what actually happened at Comdex, he's reacting in the way I think most weak people would react

I'm really glad that Cameron finally said "it's easy to make Joe the villain" because to me, that was the biggest weakness of the show. The drama would build Joe up, things happen, people get hurt, and then everyone blames Joe for everything, and forgives everyone else.

that marriage was failed from the start, just like Joe's in season 2

It's most likely good news. Considering his moods and that crying scene, the smile just seemed to me like he felt absurd after narrowly missing death sentence.
Also I have to disagree with the notion that Joe having HIV would be "interesting." Firstly because that would be such a cliche (of course the bisexual from…

Joe is the least boring character on this show. The rest of them are just nice, imperfect, but still plain old nice. What's killing this show, for me, is seeing desperate efforts to make us care more about Cameron, the self-righteous bore, and less about Joe.
The whole second season was that for me. Joe does something…

he really twists your panties up, huh?