> [1] The pardon would have put Nixon in a difficult position on the witness stand since he would not have been able to assert any Fifth Amendment privilege when questioned about his actions as president.
Nixon is the typical example of somebody pardon'd without an indictment. Like it would be wise to imply it could happen because it has!
There are a other trivial examples. Confederate solders weren't indicted [1]. The Vietnam draft dodging pardons didn't even name people [2] [3].
Why they would do it? I mean to nullify the 5th amendment right. Maybe you want to prosecute a crime boss so you give somebody a pardon (or immunity) so they can't/don't plead the 5th and have to testify against them.
Technically sure, you're correct. The worst kind of correct.