I almost get the feeling here that, had he been able to, Roy might have gone after Pam after he was through with Jim. Clearly he's pissed at both of them. Understandably so. However since he rarely stopped to consider that he was the primary cause for the first break-up, here he is looking for causes other than himself again. After all how could one kiss cause Pam to break off their multi-year relationship and engagement unless she wasn't happy with him or how their relationship had been? I mean, even after all this time the word "fiancee" still couldn't get into his head. Those are all the things he's clearly missed and thus it sets him on this path. Granted I've never really considered Roy to really be able to think all that anyway, but it's there from the outsider perspective.

Even going back to the scene in the show, Pam wants him to listen to her, instead he blows up, and insists he is listening when in fact he's not, nor has he really ever. Well done to keep this Roy in character like this.

Author's Response:

I think that this version of Roy might, but that he'd probably have it out of his system once he beat Jim. Displacement, you know? I really don't think Roy has processed this stuff at all, so he's still just lashing out.

And that's what I noticed in the show that made me go with this kind of attitude here: he really insists he's getting it when he's really, deeply not.