It doesn't change him much, but it's tonally inconsistent with a mercenary kind of guy who's only in it for the money.
Even the hero in an old western wouldn't let the bad guy get off a shot like that. It would have been laughed at.
Yes, there are more egregious changes, but this one symbolizes how much George changed in twenty years. And the explanation that he couldn't get the shot he wanted in 1976 doesn't hold water. There were no technological limitations hindering him.
We're damned lucky he couldn't/didn't mess with the swordsman scene in Raiders. After all, we can't have the hero shoot a guy from twenty feet away. That's not cricket!