Eh, no?
If you push an enemy into a pit you can't go to, too bad. That's the downside for instakilling it.
If you want to play loot game go diablo
Too bad this "hardcore" attitude is idiotic in a game where an item disappearing from existence can be game-breaking. It's not an expedient necessary to save you from the loss of 5 gold coins, as much as from preventing unintended showstoppers.
Not to mention "pushing and insta-kill" is only ONE of many scenarios where this type of unpredictable issue can present itself (i.e. enemies being blasted in a pitfall by a spell or a barrel exploding or what else).
