[Arakon]

it is possible.
he likely knife-swapped the backup AR2 with an original Region X. then there is a single version of the AR2 2.x in which you can press start to get around the hardware check. you can't use codes or anything, so don't bother trying, but it works for dvd-r swapping I believe.
he prolly then knifeswapped to get the DVDR to boot.

however, he won't have a PS2 for long anymore if he keeps doing it this way.
the damage caused to the drive door mechanism by forcing it open several times will sooner or later cause it to fail.