Not sure the particulars of your friend's situation, but some slot machines have a Jackpot that increases in value the longer it hasn't paid out. If the machine

Not sure the particulars of your friend's situation, but some slot machines have a Jackpot that increases in value the longer it hasn't paid out. If the machine happens to hit a stretch of not paying out the jackpot for a long time, the EV of playing actually does become positive (assuming you can bankroll yourself until you hit the jackpot).