That's too harsh. If a thing's unplayable, how do you call this a game?
At this point, I've seen plenty of jam games with unexpected game-breaking bugs that happen to a certain part of players because the bug doesn't happen on the creator's machine and does occur on others' computers. And more often than not, the bugs get hotfixed when there's a bug that prevents playing even a tiny part of the game whatsoever (at least from what I've seen thus far).
I say, as long as the bug fix doesn't alter the intended experience of the Jam release, you can send a fix. Like, hell, isn't that a shame to just turn away at the start cutscene? I didn't even get to make a button input.