My bf has gone through the process with trek before. It worked really well for him. He cracked his road bike frame in 3 places. He took it to a bike shop and they did the insurance claim. Then he got a new bike. This was in about 2003?

His twin brother, however, did not have such luck. He had somehow tore the derailleur hanger off. He too went through a bike shop. He KNEW that his bike had NEVER been in a crash. Somewhere between his taking it to the bike shop and it getting to trek, there was some foul play. When trek received the bike they claimed it was compromised and broken, and then did not send him a new bike and kept his old bike. He is currently bikeless, this was probably in about... 2008?

I guess to avoid the second situation that the brother encountered i would recommend to document the damage before it leaves. Take many pictures so that if anything does happen to it when trek gets it, you might be able to prove that it was not in that condition when you took it to the bike shop. But in your situation it doesn't sound like that will be a problem.

I think that it may have been just bad luck, and that usually it is a pretty easy process.