Learning to ski is certainly a particularly strong example of a case where you're likely to have a lot of false positives.
But, honestly, even with something like hiking, tripping over a tree root or something like that isn't exactly rare. I've taken a ton of spills over the years and fortunately nothing worse than some minor bloodshed or maybe a twisted something was involved. (And the one time it was something more serious I didn't actually fall but did have a serious bone break.)
I've been on the fence whether I ought to enable the feature on my watch.
It's not too difficult to solve actually. They could monitor for movement after the fall. If the person hasn't moved or has moved, but hasn't got up, then it should announce a warning (with enough time) before calling emergency services.
If they got up and have started walking again, its a false positive, or they don't need automatic help.
Learning to ski is certainly a particularly strong example of a case where you're likely to have a lot of false positives.
But, honestly, even with something like hiking, tripping over a tree root or something like that isn't exactly rare. I've taken a ton of spills over the years and fortunately nothing worse than some minor bloodshed or maybe a twisted something was involved. (And the one time it was something more serious I didn't actually fall but did have a serious bone break.)
I've been on the fence whether I ought to enable the feature on my watch.