"So, we are to believe that Rudy has evidence detrimental to Joe Biden that he has held back? Yeah, sure he does."
If (big IF) Rudy has any such bombshell, he's saving it for when (he hopes) he gets called as a witness for the defense.
Of course, if Trump's attornies have any common sense at all, that's not likely to happen but I think Rudy's hope was to be the one to save Trump by becoming the 'star of the show' with his phony video tape with ex-prosecutors. Trump was probably thinking the same thing.
Who knows if such a tape even exists . . . or if witnesses will be used. I'm just thinking that Rudy is way to toxic to be any use to Trump's defense regardless.