That, Sir, would indeed be an epic failure.
The requirements for this achievement are plain random though (how could you manage to shoot someone to exactly one hp and KNOW it?
Or even meet someone who has exactly one hp and know he'll be the one granting you the achievement if you let him live?) and encourage bad playing (waiting for anyone to shoot you until you finally have the achievement) which isn't fun at all.
Therefore I'm against the basic idea. :- /