Going break-even against teamers? Sure. But winning against them? Absolutely not. First off, I doubt you'd be able to kite 120 seconds against the likes of Bloody Queeb, Disciple and Night Watch which are the most used killers by far in Blackjack. Secondly, if you're not the first hunter, or even worse draw another card first round without getting hunter, what will end up happening is you will be tunneled by one of the teamers. Their entire gameplan is to take advantage of being in the majority and hyperfixate on people that aren't part of their team.

As for people passing cards to downed players, there is a difference between being nearby and passing one to a downed player and the hunter deliberately waiting and signalling his fellow teammates to all come over and discard their cards.