This term gets thrown around far too often.
I read 'head case' as a wacko who disrupts the locker room or does some stupid shit on the ice resulting in bad penalties, fights, misconducts, suspensions - like an Avery, DeAngelo, Carcillo, Torres.
I don't think it is fair to throw Laine in with that crowd.
I definitely agree that he cannot be called a 'low risk' investment, because he very well could never play again and cost 8.7mm against the cap. He should be viewed as a 'buy-low' candidate where the cost to acquire a talent like Laine is extremely low.