I witnessed this when I spent a month inside the offices of a large Japanese company in Kyoto. In that month there were three different dinners out for the whole office, all of them involving alcohol.

One of the engineers told me as an aside, because Japanese culture frowns on contradicting or questioning one's superiors, social drinking was a tacit mechanism where people could express their doubts about project direction and such without repercussion, as another part of the tacit rules were that what someone said while drunk shouldn't be held too strongly against them. Even after a few sips people would get more boisterous and the buttoned-down civility would drop. I didn't speak much Japanese so I can only imagine what was being said, probably something like "Boss, I'm not too confident that spending so much time adding the suchandsuch feature is worth delaying the project, but I'm just a junior engineer so I don't know what I'm talking about, hah hah. Kampai!"