I've seen GIs knocked completely off 2.5T trucks by the static charge from CH47s if they failed to discharge the static buildup. It's quite a fall from the top of a fully-loaded truck to the ground, but airborne troops cannot admit pain.
I used to do lots of sling work in 206s in the GOM, and always briefed the roustabouts about hitting the hook quickly with the becky, but some never learn, and got a jolt even down here in the humidity.