[KavMan]

Did Mueller give Comey a get out of jail free card?

I forget what it is called! Someone rejigger my memory!

& can TRUMP void that?

[Yo-Yo]

Did Mueller give Comey a get out of jail free card?
I forget what it is called! Someone rejigger my memory!

& can TRUMP void that?

I believe the word you're looking for is immunity.

And as a general rule, no, Trump cannot rescind immunity once given.

Well, he can, but at trial any information gleaned under immunity will be thrown out of court.