Metallica’s James Hetfield was visibly furious throughout his entire performance at the Grammys yesterday, and for good reason.

As reported by Tone Deaf yesterday, his microphone wasn’t on for his onstage collab with Lady Gaga for ‘Moth Into Flame’. Now, according to TMZ, the blame can be laid on one single person: a stagehand unplugged it accidentally.

The incident lead Hetfield to kick away the mic stand at the end of the performance, and throw his guitar away in anger. As we mentioned yesterday, it also looked as if he tore strips off someone at the side of the stage, no we know who that was – welp!

The performance didn’t exactly get off to the best start either. Laverne Cox, who introduced the pair, didn’t actually mention Metallica during her speech. She did take to Twitter to apologise though…