I’m as surprised as you are. He’s always seemed like such a calm, mellow customer.

MSNBC talk show screamer Ed Schultz had a meltdown in the network’s 30 Rock newsroom, shouting at staff, “I’m going to torch this [bleep]ing place.”…

A witness told us, “Ed was furious the network was running election-night promos and he wasn’t in them. He’d been arguing on the phone with marketing, then he slammed down the phone and exploded. It was like Mel Gibson had entered the newsroom.”…

Fuming Schultz was immediately dragged in for a meeting with NBC News President Steve Capus and MSNBC President Phil Griffin following his Aug. 12 meltdown.

Our source added, “Schultz was told: ‘If you do that again, you are fired.’ He broke down crying.”

Reasons to doubt that the story’s true: (1) It comes from Page Six, which of course trades in gossip and has a history of dueling with MSNBC hosts; (2) Two weeks between the alleged meltdown happening and news of it leaking out seems like a long lag time, no? (3) Could even Big Ed’s ego be so fragile that he’d react this way to not being given a two-second mention in a promo? That seems … well, actually, scratch that last one.

Any reason to think the story is true, apart from the traditional reports of infighting and personality clashes and even occasional on-air pissiness among the talent at the DNC’s favorite network? Actually, yeah. Here’s video from “Morning Joe” clipped by Inside Cable News back on August 13, the day after Schultz’s alleged tirade. ICN says Scarborough’s parting line struck him as inexplicable at the time — but not anymore. What a catch.