In reply to Andrew G: It may be a little late now but for the future,do not take chances ,if you need to get close to a child or a vulnerable adult say putting on harnesses ,always get a parent,staff member or other adult to be there with you when you do it .
I taught outdoor activities to adults with a learning disability for many years,and consider that I was experienced with this group ,on one occassion whilst fitting harnesses a young man shouted loudly "you just stroked my bum "fortunately I had requested this young man's carer to witness me putting on the harness,no case to answer ,but this could have been serious.
In sixteen years instructing in a climbing centre never once did a parent object when I asked them to watch me if ever I needed to get close to a youngster.
Use the same rules as teachers Do Not Touch if it can be avoided,if you must touch get a witness .
Hope this stops someone else facing the same problem as your friend