opening doors

while i was waiting for a meeting in the cafeteria, i saw a guy in a electrically powered wheelchair roll up to a set of double doors. he went to the door on the right (as is the commonly accepted practice in north america) and proceeded to open the door. being in a wheelchair, this was a non-trivial task. he turned the doorknob, and reversed the wheelchair, thus pulling the door open. before he was able to position the wheelchair to roll through the now open door, a woman coming from the opposite side of the doors came along. rather than using the door on the right (which would be the door not yet opened by the guy in the wheelchair), she choose to hasten her pace a bit so she could enter through the door already opened by the guy in the wheelchair. the wheelchair guy had little choice but allow the woman to pass through the door he had worked so hard to open. now, i know that guys are supposed to open doors for girls, but where should we draw the line? when a guy's in a wheelchair?