If you have reason to continue and land knowingly unstable beow 500', then there'd better be a very good reason indeed - i.e. where to go-around would result in compromising the safety of the aircraft (e.g. severe weather/fuel exhaustion/imminent security breach of flight deck etc etc).
Be careful here Gary, this exact situation led to this chaps first encounter with Management! (the severe weather bit, or at least that was his defence)!