I absolutely think there is financial liability after your buddy trusted the judgment of the LBS. Same as there would be if a car repair resulted in a similar disaster. Just a heads up about what you read here: There are owners of lbs and so on, on here who naturally want to disclaim liability and do so loudly and vigorously, so read all replies and think them through. I would have him write a courteous letter to the LBS and to Trek first, with specific info and pictures. I would then gather evidence and go to small claims court if no restitution was forthcoming. He is welcome to PM me if he needs an overview of how to go about small claims, but I think that the letters may bring some response.