iserith
Magic Wordsmith
Like I said: It's not whether you can avert the TPK, it's whether you can do it without destroying your own credibility. Friendly NPCs coming out of nowhere to save the party, or unintelligent monsters mysteriously declining to kill the PCs, is a really bloody obvious sign that the DM is bailing you out of a jam. From the player side, that sort of thing kills my interest in a campaign. I'd rather just eat the TPK and make new characters.
I'm of the same mind as a player. The DM didn't telegraph the difficulty well enough or did and we still made decisions that got us into a pickle. Either way, I would prefer to take my medicine than have the DM bail us out, however subtly.
When it comes to TPKs turning into capture or something like that, I'm fine with it, but only if the DM telegraphed that possibility in advance of it occurring.