I agree with TrackSmarts assesment. Unless the case was absolutely crushed, there is no way your bike would have sustained damage from the case or the airline's bagage handling.

BTW, does the bike have a very light, thin wall aluminum frame? If so, these have a reputation for failing by cracking as they are made for extreme lightness rather than durability. If the bike is still under warranty I expect you might have a better claim against Wilier or their importer than against Thule.