i was searching for mike's appearance on letterman (looks like he didn't appear) guess you can't make fun of someone that gets hurt. but i re-listened to everyone's bit, and mad-dog said the show was 39 days.. so maybe the 42 was added later.
mikes accident didn't seem to add any days to the production, so maybe there is somthing to the rumor that another worse problem comes up. "things get worse" from the early show..