More like 8 hours since traffic to Anaheim and back will be horrendous and extra time for TSA. He’ll need at least 3 hours extra plus extra hour to get from parking structure to park. I guarantee you will miss your flight if you time everything wrong. Best thing is go on one or two must do attractions, then whatever has no line. Shop and leave immediately. You may only have 3 or 4 hours in the park.So you suggest he/she sit in the airport for 5 hours instead?