I think the rules in the UK are very clear. The rule is NO STOP with stop allowed. Watch this years SSDT , a trial that is marked under the no stop allowed rule , and the top riders were stopping and then hopping the back wheel sideways about a foot before setting off again at certain sections .That in my opinion is not stopping , stopping is when you have not moved for more than about 5 minutes which is still not really stopping it is a brief lull. I hope that clarifies the current system. If stopping was stopping Doug Lampkin would have had quite a few more marks than he did along with plenty more of the field of riders. Rolling backwards is OK as long as the observer on duty thinks that it is.
Remember , as long as the observer follows his own set of rules and applies them exactly the same to all participants , then it does not really matter what the actual rules are.