Calling the VP, if he's not absolutely necessary for the success of a prosecution (i.e. he's the key eye witness to a murder), is most certainly grandstanding.
I would be very, very leery of allowing this to proceed and not fighting it with all necessary vigor.
of course Fitz would reject a plea, the Dems don't want a plea - this story would be over in 72 hours with a plea. They want this trial, these court challenges, they want it dragged out - and Fitzgerald is giving them what they want.