I honestly can't remember any time the game has done this to me. It's happened, I'm sure, but these moments never seem to stick with me for some reason.
The dice are really against me on my honour run trial. Not only did I have to buy a trap disarm kit and thieves tools for the very first time since early access, because rolls of 1 and 2 depleted my stock, but now on the opposite side : I had carefully planned the grove attack to knock Minthy out, placing my monk PC and fighter outside the gate to wack her, casting silence before the gate to keep her away from there. I get her down to a dozen HP and then 3 tieflings on the wall all shoot her and all of them hit. So she's dead. And no way to redo that. Suddenly I 'm not motivated anymore to continue HM. Going to Act 2 without Minthy just feels stale.
I feel your pain, lol. Had the exact same thing happen! Nowadays, if I beat the goblins at the grove raid I try to ignore until the rest are dead, and it's still tough sometimes! Someone should make a Sapper Minthara mod so it'seasier, because those refugees seem to think sniping suicide bombers is a waste of their infinite arows!
I consistently run into another issue with her though: not being able talk to her after saving her in Moonrise, which prevents recruiting her. I haven't figured the cause or a direct solution, but fortunately I don't do the single save thing after getting my gold dice, so I can just reload and that works, for some reason.