Originally Posted by miamijim
User error. You shifted that baby into the spokes.
C.S.I. Jim says:
1. chain is on large cog indicationg a shift into the large cog.
2. lower pulley wheel is missing indicating a shift into the spokes
3. If you take a picture of the body of the derailleur from an angle showing the lettering I'll pretty much gaurantee it has scrap marks on it. Scrap marks indicate prior damage.
4. owner states "I was cranking up a hill' thus implicating himself in shifting into the spokes.
Sorry....
Did you notice the pin sticking out of the chain? Look towards the top of the large cog. I didn't shift at the time of the incident, or a even few rotations before. I'm sure when the RD let go, it moved the chain. The RD was operating properly. Now chain damage cause by me earlier? That's a more likely probability. I'll look for scrape marks on the RD, but I've never dropped the bike.
It seems the concensus here is that Trek should not be responsible, and I was looking for a few unbiased views, before I told the LBS to go ahead and get the replacement frame. Thanks to every one that replied! Hopefully everyone who reads this will take a little extra care to examine their chain for problems on a regular basis, and check their RD.