I think it's just due to the sparse nature of that track, what you're seeing in those 'louder' waveforms (front left and rear left) is mostly transients from the drums, especially the channel that ends up being the rear left channel which is almost exclusively drums. I think when you listen to the mix in totality the drums don't sound overly dominant, at least in my opinion.
It's not just due to the sparse nature of that one track...here are all of the supposedly 'wrong' tracks (1-4, 6-7), concatenated together as one .wav file. The front right channel is rather consistently lower in level compared to the rest. And so it would stay that way if reassigned to the surround right. A strange mix indeed. Neil was probably baked when he approved it.