John Hargrove

A person whose name you use for cover when you accidentally say something disparaging about a particular person in a more-public way than you initially intended - especially when the person in question hears or sees what you say about them.

Person One: "This guy is such a jackass."
Person Two: "Dude, the phone's not on mute!"
Person One: "Umm...yeah, like I was saying, John Hargrove is such a jackass."