He was on that exact gulf air flight and he was still denied entry. As you said, gulf air does not give a BP in advance. He couldn’t believe it but they insisted on refusing entry. If the computer didn’t have a same day pass to scan they wouldn’t do anything.
As far as I can tell -- unless he was in Polaris business class on the inbound technically he would not be admitted to the lounge.
If he was in Polaris they were wrong to deny entry.