Unclear who the man was, or even if the whole thing was scripted ... but either way, Moxley wasn't having it and let that guy know about it.
"Well, he ain't change much," legendary announcer Jim Ross said on the broadcast.
The crowd absolutely ate it up ... cheering on Moxley and giving him a round of applause for going after the heckler.
Unfortunately, this isn't the first time we've seen wrestling fans shout out stuff at an AEW event -- a fan previously yelled a homophobic slur at AEW star Anthony Bowens. Luckily, in this instance ... the fan's outburst wasn't as serious as that time.
Jon then went on to tell the crowd how he's been fighting demons his entire life and has the physical and mental scars to prove it ... but says he doesn't run from them, as they made him who he is today.