Timothy has always never liked the position he was in. He was always nervous around Moxxi in TPS, most his lines still line up to his character save “kill lines”.
This is kinda’ the case with all the characters. Their NPC behavior is always far weaker than their playable behavior (save maybe Brick in Commander Lilith DLC.)
Most cinematics and story elements in 2 and 3 would go very differently if the characters were accurately represented as per how you can play them.