The plastic could cause a problem if the trailer was damp before it was applied. The moisture can get trapped behind the plastic and literally boil the paint when in the sun. I would first check with a good bodyshop/painter. An automotive shop will do, then my insurance company. It sounds to me like the damage was caused by someone else. I would be livid if it was my trailer. There is no reason you shouldn't have been contacted to come and move it before they did this work...This could be a very costly repair and should not be your responsibility. Now in looking at your trailer..are you sure it even has a clear coat finish? Unless it has full body paint or at least painted end caps, not colored gel coat it won't have any clear coat. In any even I would still get a professional opinion and go from there.
B.O.