I think this is a bit of a... reach, not knowing the man personally in any way.
I don't know if Chris Avellone was passive-aggressive. But it does seem possible that he was unable to work many hours in a lead role due to his family health issues, but still wanted to have a large influence on the games Obsidian developed, and that this created problems. That would explain the talks he's been giving recently about how to construct the optimal game development hierarchy that gives everybody a voice.