"I mean he was livid. I mean, he's aged really well and he's a pretty chill guy, but the first five or 10 minutes in that dressing room was not a lot of fun."
Despite the mishap, the group powered through as best as they could as they didn't realise the extent of the difficulties.
Speaking to Late Late Show host James Corden - who also presented the Grammys - Lars said:
"Well, in the heat of the battle you're out there you're playing when it's a technical issue you don't really know is it going to the house, is his vocals going to the truck? Maybe it's the monitors, so you just gotta keep playing."
"We fought through it, and, you know, with the fire and Gaga in my lap for a minute at one point, it was just keep going, keep going, keep going. So we just fought through it, and a lot of people said it at least made for great television."