Robert Plant’s personal sound engineer, Roy Williams, was on the desk too! I suppose it was a case of one hand each on the desk, and the remaining digits meeting to form a bond of fear and mutual respect. Yes I mean holding hands.
Pro Sound News report this

As Big Mick admitted afterwards, “The pressure for this gig was definitely on!”

With that in mind, audio for the show was supplied by various UK-based sound rental companies, including Britannia Row and Major Tom Ltd., the latter of which brought an enormous Meyer Sound PA based around Milo and Mica loudspeakers, while the former had, among other gear, a Midas XL8 digital mixing system on hand for the FOH position and a Midas Heritage 3000 handling monitors at stage-side. Making an unofficial real-world debut, Klark Teknik’s DN9696 high resolution hard disk recorder was used to record the event for posterity.

To be fair, more than a few (reporters) remarked on rough spots in the mix early on, but The Independent, Billboard and Uncut all conceded that the sound was on track by the time “Black Dog,” the evening’s third number, began–and fans quoted in The Telegraph went so far as to call the evening’s audio “fabulous.”

“It was like a rollercoaster ride,” Big Mick laughed. “You had better hold on tight!”

Fantastic. Audiotechnews knew he wasn’t going to get tickets, so decided to forget all about it. All of a sudden, he wishes he’d had the kick drum fader, and maybe some toms.