"Dave just has to have them sign a waver stating he is not held responsible if something happens."
That still isn't a 100% reliable and won't stop some donkey from trying to extort $$ for their stupidity/carelessness.
Took a bud with me grooming one night and came upon a guy with his MXZ off the trail, which was an old RR grade, so about 10-15' down and steep. Big time stuck, his pals couldn't get him back up out of there. We stopped made sure everyone was o.k. and went on our merry way, those guys stood there looking like a deer in the headlights. My bud says, "You could have pulled him out of there no problem." To which I replied, "Yes I could have but if I put so much as a scratch on his sled he may have gone after the Trail Authority looking to get a new sled out of the deal."
