They give two reasons: (1) they were bullied before, which is a weak argument; and (2) they were promised a full audit for their votes and that promise won't be delivered--a slightly better argument. I have no idea whether they are allowed to rescind their votes once the meeting is over, but my bet is they probably can't any more than a Congressman can, or you or I can. My suspicion is that they know this, and this is empty virtue-signaling to make it up to Republicans.
I've read elsewhere that the Dems on the board are saying it's too late and that the vote has already been certified. Again, I have no idea whether that is true or whether it is reversible.
I see your point, though. They shouldn’t have allowed fear to influence them. But in my youth, I lived in that kind of neighborhood to be closer to work. Most people who write comments here would have done what Palmer and Hartmann did in that situation.
Canvassers in those neighborhoods need to be young, in very good physical condition, very well trained in self-defense and have a large contingent of tough security guards with them (trained fighters with cameras connected to the Net, remote security watching over them, etc.). They really need a small army with them. They’d be surrounded by a foreign nation resembling Winnie Mandela’s mob.
Election board members in those neighborhoods, even. Trying to do several things at once here.