The episode had been taped before the allegations began to surface about Bill Cosby. So, there's not a problem with her being fired. Donald Trump didn't know, no one knew, so it's understandable.
The problem though is that yesterday, LONG after all the stories became news, Donald Trump sent out a thoughtless, crass Tweet. He explained that the episode was taped much earlier -- but that Ms. Pulliam still should have called Bill Cosby because it was for charity.
How brain-dead does Donald Trump have to be??? (And I know that in some circles that might be considered a rhetorical question.) Even though the allegations may not be true -- for all we know they may be. And we also know that Keshia Knight Pulliam was on the Cosby Show, and it's not unreasonable to think that maybe she knew something. And maybe, possibly that's why she hasn't spoken with him in a long time. Or maybe -- well, it's also not unreasonable to at least think the worst is possible, even if (hopefully) unlikely. But at least before sending out a freaking "Tweet" about what she should have done and called him, Donald Trump KNOWS today -- when he sent the Tweet -- that there might well possibly be a very valid reason that the young woman didn't want to call someone she worked closely with and hasn't spoken to in five years. And to write publicly that she still should have called him is galling.
Maybe she hasn't spoken with Bill Cosby for completely some other reason, having zero to do with the allegations. It's absolutely possible. But for Donald Trump at this point to ignore what's been relentlessly and sadly in the news as an equal possibility and toss off what she "should" have done only serves to cement his deeply poor growing-reputation as a sad joke.