Depending by your nationality, but probably you are eligible to enter with a "visa exemption" 30 day stamp, that you can extend again by 30 more days at local Immigration
if you want to be "extra" sure, in Penang could ask you to show bank statement with at least 50,000 baht; and, along with copy of your apartment lease, copy of house book (tabien ban) and signed copy of owner's ID.
Show up in the morning from 9 to 10am only and you can pick up your passport the day after, from 2 to 3pm only.
He could try to do that (even if actually is not a visa on arrival but a visa exemption stamp). Just ask the Immigration officer not to stamp USED on his visa and give him a พ30 entry stamp.