Ange Postecoglou handed out the 'mate' treatment in response to a question about Callum McGregor's mistake during the win over Kilmarnock.
Celtic restored their 12-point lead at the top of the Premiership with a resounding 4-1 win over the Ayrshire outfit.
Skipper McGregor was uncharacteristically caught in possession for Liam Donnelly's consolation strike.
Kyogo Furuhashi had put the Hoops ahead after just seven minutes while Daizen Maeda and Matt O'Riley (two) piled on the agony for Derek McInnes's men at Rugby Park.
After the game Postecoglou was asked about McGregor's error in the lead-up to the Killie goal.
"He was caught in possession in that area," he replied. "I thought up until that we were really good at playing out of some tight areas.
"That’ll happen – the pitch doesn’t help with that but I thought we handled it OK. I thought the boys scrambled and almost kept it out.
"But he’s allowed one error in his career, mate."
In summarising his side's overall performance, Postecoglou was particularly pleased with their first-half display.
He said: "Outstanding first half. The boys were bringing their football, our attitude and our intent. It was a big game last week so you're kind of looking to make sure the boys are still focused and it was outstanding.
"Second half we got a bit sloppy, never really got into any sort of rhythm, lot of stop-starts. But overall, knowing the challenge that was there before us today, a great job."
Our Celtic Digest newsletter brings exclusive content directly to you rather than solely through the website. You can already find us on YouTube, Twitter, Facebook, TikTok and Instagram but we will also send bespoke opinion pieces and special features every day directly to your email inbox every evening. Not only will you receive this article from Sean Martin, Tony Haggerty or Aidan Macdonald (or, sometimes, all three) but you will also get easy access to our best content from the last 24 hours too. It’s a great way to keep up to date with what’s happening at Ange Postecoglou’s Scottish champions. To sign up, simply take five seconds to type in your email here. Simple!
