I've seen multiple dead steelhead that had been CnR'ed. The "worst" two I can think of were both in the upper Hoh and both had Gami's in the back of their mouth where the angler had cut the line at the mouth (the best option considering...). Personally, I don't ever remember deep hooking a native. I've certainly killed a bunch of little ones that have had their eyes, gills, tongues, and brains pierced with "big" hooks.

The claim that the average banky fly guy is landing fish quicker than gear guys in a boat is WAY off. Boats will almost always land fish quicker and with less stress to a fish than anyone on the bank, regardless of technique used to actually hook the fish. Most hot fish that head downstream generally get chased in the boat to some degree and don't have to be pulled all the way back up to where they were hooked. There are obviously exceptions, like that horrible video someone posted (and then took down) from a guide's boat a few weeks ago.