They were in the student lounge/study area and not in the classroom. If you were in your leisure time among a group of English speaking people in a Chinese comp

They were in the student lounge/study area and not in the classroom. If you were in your leisure time among a group of English speaking people in a Chinese company, it is likely you would speak English. At the end of things, who cares, do you want to monitor all your colleagues' behaviour while they are in the lounge or in their leisure time to make sure they fall in line with mainstream company views? I'm glad companies don't force themselves on employees during leisure time.