What's the difference between "gangster" and "gangsta?"

For Jeopardy contestant Nick Spicher it was 3200 bucks.

On last night's show, he was given an answer which should have combined Coolio's biggest hit "Gangsta's Paradise" and the classic John Milton's book "Paradise Lost."

Nick said "Gangster's Paradise Lost" and host Alex Trebek initially accepted it.

However, later in the episode, he was stripped of the money he got for getting the question right when the judges decided he needed to have said "Gangsta's Paradise Lost."

Do you think he should have gotten credit for his answer?