Wow, that's a brilliant argument! According to that list of headlines Arthur reads about Brian, he was busted for coke in 1973 and the recording sessions are taking place in 1974. So he probably was still doing coke during the recording sessions but certainly not as deeply as he is shown later in the film. Brian's got a (huge yet) fragile ego to begin with and mixed with the paranoia we all know that cocaine is famous for, I agree that he is more aware of Jerry (and Trevor and even Eton) than Curt. I happened to watch a doc on the making of Who's Next over the weekend and in one interview segment Pete Townsend was talking about the band coming to New York to record at the Record Plant. He said that it didn't work out because Kit Lambert was starting to get into smack. It was so telling that Pete was so dismissive and derisive in his attitude toward heroin. He said, referring to the time in question, maybe 1970, that although he drank a lot, he hadn't done drugs since 1967 but he'd never done narcotics! I had to think about what that meant, since it seems that drugs is drugs but apparently in the hierarchy of drugs, even to this pill popping ex-Mod, heroin was somehow unseemly. Brian, being an ex-Mod too, probably sees coke as a method to be more productive, it's almost a work-ethic drug, compared with the lazy slackers that use heroin. Cintra Wilson makes some interesting comparisons between heroin and cocaine addicts here.