Addiction to Psilocybin mushrooms preventing promotion to Associate

My friend and I were sitting in a kinda empty business class lounge before an international flight, but he took way too many Psilocybin mushrooms before the flight and started freaking out.

His girlfriend was with us and asked him if he had taken anything, and he said very loudly that he had taken shrooms. His girlfriend then went on to shit on him for being on shrooms, and started threatening to send him to rehab because she said he was addicted. She then said the name of his company out loud because she was like “what if drug tested you?” (Our company has never drug tested us by the way)

He’s freaking out now because he’s paranoid that someone from our company was in the lounge, heard the name of the company he works for, and snitched about this conversation to his manager or MD. Our company is very large.

This happened almost a month ago, and so far nothing has happened. If his manager or MD found out about this, is there any reason they would not have already fired him for this but also will not promote him to Associate when he’s up for promotion this year.

Does the fact that almost a month has passed and nothing has happened mean that he is in the clear? Or could this still come back to bite him later this year when he is up for promotion to Associate? I really don’t want him to leave, and he told me he plans to get completely clean and never touch any substances like these ever again, even if they have been decriminalized.