I’m sure that what he meant to say was something along the lines of there’s never been anyone who’s plead guilty to perjury who’s then had the prosecutor nonetheless withdraw the charge. I don’t know. Maybe that’s happened, maybe not. It well might have in strange circumstances where, for instance, the DA discovers a rogue prosecutor had abused process by extorting a guilty plea from someone - as in fact happened here when they pressured Flynn to prosecute his son.

The real point though is that Obama’s panicking. That’s why he’s saying something so rash and dumb.

And he’s not just panicking because of what’s already been revealed.

He can see where this is going.

https://theconservativetreehouse.com/2020/05/08/obama-panics-president-obama-gives-political-operatives-and-media-talking-points-to-protect-him/