James Corden may have been a POS at one New York restaurant — according to the owner, anyway — but another celebrity chef tells a different story … saying the dude is expensive.

Curtis Stone defends JC — tells us at LAX this week that he’s only been great at his establishments … though it’s unclear which ones. Curtis owns several famous locations around the world, and Maude in Bev Hills is perhaps the jewel in the crown.

In any case, CS says his experience with Corden is very different from what he described Keith McNally — who owns Balthazar and who put the host of the ‘Late Late Show’ in the fight.

Speaking of which, we asked Curtis if KMN broke an unwritten rule among those in the service industry, which is to protect the privacy of customers, especially celebrities, even if they’re a little rude.

Check out his answer…he says they should be safe places. 👀

McNally’s motives have been questioned throughout the debacle – frankly, he’s been reeling like a fish, getting his ban back and even showing sympathy toward Corden and extending an olive branch, offering a free meal if the guy properly apologized to the servers.