I think I latched onto the character because of that scene. That dismissal made no sense, because Weir is smart enough to know she should listen to everyone on the science team about such things. Personality clashes aren't an excuse, because hello, has she met Rodney McKay? ;)

The later, rather casual consent to threaten to torture Kav because they thought he was a spy for The Trust was rather chilling. Especially since it was stated he'd sent messages, but they never explained who they were to or why it was such a secret, or at least not that I recall. It was just a plot point that was never addressed properly.

Just seemed like the writers wanted a convenient "we don't like this guy, so we'll use him as a scapegoat instead of creating a credible reason to suspect his motives" character.

I haven't seen much with Kavanagh in fic that doesn't make him the convenient bad guy/idiot the writers did, so anything that doesn't fall into that trap would be much loved.

There might also be a small factor that I seem to have a thing for solder/scientist pairings. ;)