I had the Hinox thing happen to me in Master Mode Trial of the Sword ... I had him down to about half health, stunned him with Stasis+, shot his eye, and then rushed in as he was falling so I could get the last couple of hits on him before I could get his eye to pop out... however, I got too close as he was falling and touched (yes, just touched) his leg before his butt was on the ground, and it killed me instantly. That Hinox is easy all things considered ... and it was totally my fault for rushing in too fast ... but still, that's just a cheap way to die.
Another time - a much funnier instance - I was in a hectic battle with multiple enemies at night, and then some stal-moblins appear, so I just ran. I was near a cliff/ledge so I ran for it and jumped off to start gliding away to safety. I had just a few hearts left but was thinking "it's all good, I'm free now" ... then out of nowhere one of the stal-moblins shoots me with his bow (I was pretty far away too) and I just dropped like brick out of the air and landed with a splat and died. I actually laughed pretty hard.