McCain was ordered to refuse as were all other POWs by Admiral Stockdale who was the Commanding Officer of all POWs inside the Hanoi Hilton. Admiral stated that no POW would go home early unless all POWs were going as well.
McCain was under a general order. It was not of his own volition. That makes all the difference.
Not everyone obeyed that order, which indicates choice was involved whether you can recognize that or not.
McCain earned special attention from his captors because he was more than merely a captive, he actively resisted. It's only from a position of ignorance about his actions after being captured, actions confirmed by Admiral Stockdale, that anyone can besmirch how McCain comported himself after capture.
Mccain made 32 propaganda videos for the vietcong.... is that the resistance you refer to? How many did Stockdale make?
Admiral (then a USN Captain) Stockdale and all other POWs inside the HH confirmed the only way to come home early was if Admiral Stockdale granted permission; there was no other way around it. There was very few releasees. One was a Seaman Apprentice named Douglas Hegdahl III who had spent night and day memorizing the names of 256 aviators into a rhyme and jingle. He was ordered to be an early release because he had those names to pass on to his debriefer when he got home.
McCain was never ordered to early release although the enemy offered it to him. He refused because of the standing order given by his POW Commanding Officer James Stockdale.
From Admiral Stockdale's book p.254:
There was little concern in any American's mind about the possibility of the Vietnamese throwing anybody out to defame him; we now knew the Vietnamese well enough to be sure that any early releasee would have to buy his way out by groveling on his knees before the Communists, bad-mouthing America. I gave their new release program a name: FRP -- the "Fink Release Program," and that was the way it was to be known. I also issued an order that started on its way to the other cell blocks of Las Vegas and with subsequent movers to the camps elsewhere in the city and outside it: "No early release; we all go home together".