We used to layout and work on pretty much vertical ground. I am glad we don't anymore. Things got too crazy. I'm not going to criticize them for that.
Steep is what you are not used to working on. I was delighted when I went from Oregon to the Midwest to find that 30% was extreme. A lot easier on the body.
Trying to unkink the line while the helicopter was pulling it? I wonder if the guy was trying to show off? The one with the radio looked plumb worried to me and that would be real.
High stumping the leaner? I wouldn't worry about it unless I found pieces all over the place. Then we'd have a civilized chat.
But, motorized carriages are a weak link. They take a lot of abuse, but will break down more than anything else. You bang them around too much and parts will come loose, like the radio antenna and they won't work. The other common breakdown is the clamping mechanism will freeze and you've got 900 pounds of metal stuck on the skyline halfway down the hill. I've seen a crew repeatedly ram the carriage into a tail tree, then wonder why it broke down a lot. They really need to be more careful with it.
A twister is a doubled up piece of haywire, hooked from the tailhold to another tree or stump. You grab a thick limb, about 4 inches thick by 3 feet, put it in the middle of the two lines and twist them tight. This reinforces the tailhold and makes it less likely to pull. The tricky part is undoing the twister.
We have shallower soils here and one (big enough to probably not be gypo)outfit really goes crazy with the twisters but they haven't had problems pulling over tail trees either. Well, till the snow melts, this show is all the logging I'm going to be around. At least I'm not having to wade through the brush to view it. Much easier on the shins this way.