Get Back has sent me down a Beatles rabbit hole as of late. I love me some James Taylor too... and reading this kind of retrospective is fairly heartbreaking... but you know... it's what it is.
edit: I did a little more reading... JT is feeling pretty bad about this, and no doubt he gave John some opiates... but it sounds like John's exposure may have pre-dated JT's time in London by a little bit.
Still sucks.