I agree, it sounds like the guitar mic pre was distorting. The rest of the band is very clear but the guitar is over-modulated in a way that is reminiscent of a recording issue. It doesn't sound like tape distortion as it's not compressed enough. Great performance all the same.Something to right there, and I suspect it isn't the amp alone were hearing. In the beginning there is something that sounds like a phaser or flanger, and also it sounds like bad mixing to me, as it changes in a way the amp probably wouldn't. At the start, terrible too hot signal, there is a not exactly ghost note, but suddenly one very clear note in the intro, levels change quite a bit throughout.
I'm thinking we aren't just hearing the amp.
That sounds like it was recorded way too hot.
I'm sure Page's guitar tone was much better at the show.