Would it even be possible for a relatively junior petty officer to "take command" as OIC on a Swift? I'd suspect that Sandusky is doing a bit of resume-polishing here.
As far as I've ever heard, the OIC slot was always held by a j.g. or a lieutenant. A very senior chief could perhaps do it temporarily. I seem to recall that Sandusky hadn't even made 1st class.
Chiefs and PO1s would command PBRs. I don't know about PCFs, but I'd doubt it.
I think Del Sandusky was making a weak joke here ...