I often see "Casual" riders on the MUPs round here with the top coat/jersey round the waist with parts of it getting close to the rear wheel. Makes you wonder how they have survived so long. But one of the things I used to do on the Long enduros was to make certain that any clothing discarded was put inside the top bag of the pannier and not just in the mesh cover. It is just commonsense to me. I often saw other riders with a jacket in the Mesh of their back pack and a sleeve or some of the jacket dangling out.