Was Tim hired as a teacher or trainer? What I find strange is that it sounds like Tim was not doing any individual work.
As a very experienced programmer, I'm sure that I could increase the productivity of other programmers by pairing with them all day. However, is that actually the best and most productive use of my time? In my estimation, I think that overall team productivity would be maximized if I spent approximately 20% of my time pairing with others and 80% on individual contributions. (That's a rough estimate; it could be 25/75 or 30/70.) The article said that Tim was "patient", but perhaps he was too patient, wasting a lot of his time that could be spent accomplishing other things.
As a very experienced programmer, I'm sure that I could increase the productivity of other programmers by pairing with them all day. However, is that actually the best and most productive use of my time? In my estimation, I think that overall team productivity would be maximized if I spent approximately 20% of my time pairing with others and 80% on individual contributions. (That's a rough estimate; it could be 25/75 or 30/70.) The article said that Tim was "patient", but perhaps he was too patient, wasting a lot of his time that could be spent accomplishing other things.