I screwed up when a Beastman took a PC to 0hp and told the Player that if another of his Pc's tried to help the one at zero on their next turn with a DC 15 luck roll, the dying PC would have 1hp. I realize now that I should have had them die at zero hp and let them try to "Recover the Body" after the fight. Because of this I did not have as many deaths from melee as I should have I think.
This (nearly) happens to me a lot for 0-level adventures. I messed it up once and have been paranoid about messing it up again, but so far I think I've caught myself after that one time. Actually, my players now help me with this, since I keep wanting to default to "save the character" mode.
No biggie, really, but it does go agains the spirit of the zeroes. And the nice thing is one we all survive the funnel the DM can go back to his usual style, whatever it may be.