Rowe admits that he initially failed to recognise the singer after he humbly said he played in a "local rock band" and, upon discovering that he was in Metallica, then mistook Hetfield for his drummer bandmate, Ulrich.

In his Facebook post, Rowe says he's usually good at remembering people's names - but blames his social faux pas on drinking mimosas in warm weather and failing to control his excited dog during the "botched encounter."

He says: "Thank you for being so gracious and saying such kind things about my foundation. I was very flattered. I also wish to apologies - not just for failing to recognize you - but for not recognizing you in front of your charming niece from Buenos Aires.