@susan: I just checked it: I hear it as written in the music. It would not make sense anyway, because the first C# would double with the Lead. The Lead is what you probably hear here.
Another thing, not a mistake, but something peculiar:
Bari in measure 75 goes straight to A, while the 2 previous times of the same material (measures 19 and 35) the music says A# – A. All the other voices stay the same.
The learning track actually sings it as written, but I can’t help but wonder, if Ed Waesche did this intentionally or it just slipped.