If a stand by crew were called out, then Ground should have known that a couple of hours before flight, and with a full A/C, picked out four FF/last on, told them they were off loaded, but standby for no shows.No boarding passes issued. If still no seats, offer an alternate flight, with an upgrade. Not board them, then drag one down the isle, like a drunken footballer, and chuck him off the bus. Most flight crew would be appalled by the behaviour, and the Skipper had every right to intervene, had he/she witnessed the disgraceful behaviour of police, man handling this innocent bloke. I would have chucked them off, and let ground have it, bigtime, before I departed anywhere.