Buzzer certainly knew what had happened to his Ganger at the start of the first ep - not just that he'd died but that it had been caused by Jen taking a swing at him. After the connection was severed though it was different - they could only make predictions or even guesses based on previous shared experience.
Buzzer actually said that he'd watched the video of what happened to his ganger.
In the corridor or later on? I've just watched the corridor scene again & the only thing he mentions having seen are holo ads about claiming compensation.
Wasn't the Buzzer they bumped into in the corridor another clone though?
Possible I guess - I guess I've just made the assumption that he is the real one. If he is another Ganger though it doesn't
entirely undermine my theory of a the real person having the memories if the Ganger at this stage because he knows what happened to the previous Ganger & the only connection between them is the real Buzzer (the previous Ganger at this point having been dissolved in acid).