I'm afraid I completely disagree with this. Both as a player and a DM, I find saving the PCs via Deus ex Machina cheapens the experience far more than fudging some roles, not least because the players are actually aware that the Dues ex Machina happened.
Which doesn't mean that I won't do such a thing when narratively appropriate or the whole party ets knocked put. I've gotten plenty of use from the "you all regain consciousness in a cage" out in the past, when plausable. (If a player fails their death saves or the enemies are wolves or ghouls or something, then, sorry, they're dead, nothing I can do.) But I think fudging some rolls and HP counts on the sly is definitely the lesser of two evils here. There's only so many times the players can wake up in chains or get rescued by the calvary before they start rolling their eyes.