I finally found my copy of End of Term and have caught up. Thinking about Tim, there's a sense that on the one hand she wants to be a bit detached and above it all, but on the other she wants to be at the centre of things (unless that involves games, and we do get a sense of a certain resentment at the extent to which Lawrie and Nicola are engaged by them). Whereas, by contrast, Jan Scott really does appear to be detached and really doesn't care - or so it would seem - about her designation as Non-Cooperative Type. In fact, over the series, we get a certain impression that that's how she likes it.