Burns didn't shoot it, his client did. I don't think she was any kind of an expert. But to be honest with you I wouldn't shoot that far with any caliber/cartridge simply cause I don't practice at that distance.
As far wounding game, plenty of game is wounded on the opposite end of the spectrum... using more gun than they can handle.
I think with the premium bullets available plenty of elk have been cleanly killed with the 243.