We have a common pizza oven in our housing association and some idiot got the oven too hot, a pizza caught fire and they tried to remove it with the peel..
Did you see it happen? If not, I'm not buying the story. Melting the peel isn't something that would happen all that quickly even at temps north of 1,000F - and particularly not if there was a pizza or partial pizza sitting on top of the peel. For that matter, intact pies don't catch fire.
Here is what I'd bet really happened - someone trashed a launch, the dough ripped or stuck to the peel, and some of the toppings landed on the deck and caught fire. They then scooped up the burning shambles with the peel. That made a big sticky burnt mess on the peel which they stuck back in the oven in an attempt to burn it off in the fire. That's when the peel melted. That's what I see when I look at the remnants of the peel.