It appears that someone is making a joke on setlist-fim. We played more than two songs that night and we've never done a cover of "Free Bird". - FLS

If setlist-fm is to be believed, this show is the only time the band ever played a cover song: Lynyrd Skynyrd’s “Free Bird”:

https://www.setlist.fm/setlist/fugazi/1989/the-chameleon-club-lancaster-pa-5b9343cc.html

Any idea if that’s accurate? If so… why Free Bird? I’m assuming it must have been a Beavis & Butthead reference, like responding to a heckler or something?