If it is an unwritten rule that all fell runners must embrace nudity and dance around the field post race in birthday suits, I'll happily join in! I have gotten changed in many fields before if it makes you feel better.
I'll take note of the fence jumping rule in future. I don't see how it can be something you can be disqualified for if its not an official rule. It needs to be made clear and I think should be stated in the rules.