I never once saw Don Shula run up the score. Would love an example, but I'm sure you won't find one.
I understand it was a different era and sportsmanship looked different than it does today.
Let me ask this too. As a Buffalo fan if Allen got seriously injured on that unnecessary play, would you blame McDermott?
If Allen got seriously injured on an unnecessary play, I would absolutely blame the coaches. That play was not unnecessary, so no, I absolutely would not.
Again, the difference between 16 points and 17 points is potentially really big, a two-score game vs. a three-score game. Yeah, the odds are that it wouldn't have been an issue, but this stuff happens. You are talking to a fan of a team that suffered from the Hail Murray last year to lose a game. Bizarre stuff happens. Not often, but it absolutely does.
As for Shula not running up the score, dude, please. He loved to run up the score.
You guys tend to remember him with a halo (as I would in your place, I'm sure) but he had no problem humiliating teams that let it happen. A few examples:
9/10/78 Fins over Colts 42-0, with 14 points scored in the 4th quarter
9/24/77 Fins over Cardinals 55-14
10/19/75 Fins over Jets 43-0, with their last TD, the one getting the score to 40-0 late in the 3rd quarter coming on a 32 yard pass
11/2/75 Fins over Bears 46-13, 14 points scored in the 4th on a 58 yard pass and a 29 yard pass
11/3/74 Fins over Falcon 42-7
19/7/73 Fins over Jets 31-3
11/11/73 Fins over Colts 44-0
12/15/73 Fins over Lions 34-7
Shula had absolutely zero problem with grinding his bootheel into an opponent's face. Nor should he have. Unfortunately, the Bills were under that heel a time or two. Stop kidding yourself he was Little Orphan Annie.