What I think of Fitzgerald asking for the alternate is exactly the same as what I think of Wells not asking for a mistrial - exactly the opposite of what defense lawyers usually request. It is odd, but impossible to judge not being there or observing any of the jurors, or the voir dire.
But we aren't talking about a defense attorney, are we?
We're talking about the Prosecutor's Prosecutor, right?
Surely, he wouldn't be playing games with the jury, would he?