With Dallas in keeping with the jovial portion and spirit of the rules. This wouild be my rulebook qoute.
"All vehicles should have an adequate brake system to safely unload and reload the car from and to the trailer; all other stopping should be at the drivers risk" 
....JD
PS: after you loose a chute you quickly formulate a new plan..
I have to say..... I HAVE had more problems with lack of brake while loading/unloading cars onto or off of trailers in my life..... than pretty well everywhere else combined.... I vote for jd's rule change!
