Guitar question

[Rickenbacker]

Ok, I asked on a Facebook guitar group & seems many are (currently) stumped.
I *love* the Byrds' cover of this song, but I'm almost convinced it's at least partially in a weird tuning. Cannot figure it out though. I'm hearing what *sounds* like the B or high E-string being hammered-on but it sounds tuned down. (Listen at the 5 second mark. & it's heard again sporadically throughout) Already tried Googling tabs & all say standard tuning. I'm not convinced.
Any clues?

[bill g]

Sounds like standard to me. But there are 2 guitars, I think both 12s, one of which is harder to identify. The 2nd guitar (more background) sounds like it could be tuned down, or not always playing the same chord as the more upfront guitar. Just my, possibly wrong, opinion.