Where will this person get the appropriate tube? Do you reckon any old welder knows which type of steel, wall thickness, and butting is an appropriate replacement for your bike's TT or chainstay or whatever? Does he know how to handle the air-hardened steel? Can he order individual tubes from Reynolds, or Columbus, or some other tubeset supplier?

Honestly, these old claims have a little validity. Sure, a bent steel frame can be cold set back into shape fairly easily -- just not by any old schmoe with some tools and no knowledge. But this idea that you'll take your frame to, say, a guy who fixes boat trailers and have it welded back up after a crash? Ridiculous. Laughable.