bk said: "You can't just fire a B'way pit conductor, for God's sake. The union would not allow it, just like you can't arbitrarily fire an actor without going through the proper steps."
You CAN fire (or, more likely, suspend and thereafter fire) anyone, without regard to whether a union is involved. The issue (and I would think this subject has been discussed recently enough that it would be in everyone's short-term memory) is whether the firing was wrongful, either legally or contractually. It it was, then the person may be reinstated. But make no mistake: you can remove someone at any moment, and then suffer the consequences if you cannot justify it.
While the scenario of the question here (and I note it does not state that the conductor was on Broadway or even in a union) makes it unlikely, I think we can all conjure an example of a case where immediate removal would not only be expected but would be deemed justified. For example, if that conductor pulled a gun on a percussionist during the intermission, I don't think anyone would expect to see that conductor back for Act II.