Eh, no?
If you push an enemy into a pit you can't go to, too bad. That's the downside for instakilling it.
I 100% agree. You you push a character off a cliff hundreds of feet high, that you wouldn't be able to climb down in a tabletop game(as a DM I wouldn't let players do this), then you shouldn't in this game either. Sure it's frustrating on loosing out on the loot and I completely get that, but it's about balance(swings and roundabouts).
Me personally, I wouldn't even mind if this happened in a quest, which then meant I couldn't end/resolve it how I had 'hoped'. If this does happen I think it would be cool if the game can factor this into account and 'close' the quest and make note in the journal as to what happened'.
