What do you think? What's your preference? Do you like being saved?
I think that type of thing needs to be in the rules, clearly stated.
It's completely understandable that players get p---ed off by this, for two reasons. Firstly, if combat is supposed to be a challenge that the players can win or lose, achieving rewards for winning and being penalised for failure, this kind of GM-fiat seems to be removing the penalties, so winning is meaningless. Otoh, there may still be penalties for failure, just not PC death (loss of stuff or xp, story penalties, etc). Again, whether and how the players are being challenged, and what the rewards and penalties may be, needs to be clearly stated. Most traditional rpgs don't do this, they just fudge the issue.
Secondly it makes it look like the game is a railroad, ie it has an outcome predetermined by the GM. The players will wonder, if the GM overrules the dice now, is there anything he won't overrule to get his desired result? And if that's the case, what's the point in the players being there, do they have any power over the game at all?
As a player in a traditional rpg, I have hated it when this happened. But I'd be totally cool with it, I think, if it had been established, say that this was a fiction sim game, or, even better, a 'bad fiction' sim game. In bad fiction the hero is forever being saved by deus ex machinae, plot elements that haven't been foreshadowed. There can then be rules for how and when the hero is saved. Combat could even be taken off the table as a challenge for the players at all. It may still exist, but serve different functions. This would be getting far away from trad rpging however, which at least goes thru the motions, still.