Greg,
I agree. Not to mention any names, but I was a little surprised to see a photo someone holding a king by its neck off the ground in a vertical position - it looked like the king was about to have its neck snapped in a way some redneck would do it at a snake round-up-rodeo in Texas!
I was surprised because the guys who took/held that pic know better and are herpers and not a couple of yahoos...
When kings put that kind of size and weight on it can't be good to suspend them like that for even 5 seconds or so, much less more than once for a longer period. They don't have the type of muscle arrangement like a tree snake to really protect themselves in that position. Moreover, if a king found itself in that kind of position in the wild, it would quickly drop to the ground unless it was too far a leap (if they can judge distances like we can).
Kings are tough snakes though. Corns and rats have been known to fall 30-40' with a squirrel or bird coiled and never miss a beat. My kings will sometimes feel out a cage that's 6 feet off the ground, crawl down as much as they can, then just release and hit with a "thud!" But they are controlling that fall and just keep on moving with no injuries at all - not even shaken up.
My guess is they could handle a fall of 20-30' without being killed but I wouldn't expect to see that happening to many kings unless they're in rocky areas.
Just MO though, and I'm talking the Beasts from the East in this message.
Peace.
-John