according to the discussion it might be beneficial to take dated pictures or video of your trailer before you take it too a shop. might be a bit of a chore to do so.
however it would remove any doubt that the damage occurred with in their care. not sure i want to take it to a person that will not cover anything that happens to my rig on their property.
call it a video catalog. its a cya move. if you cant get on your roof. have someone get up there and take all the pic or video they can. might even do it every year just incase.