The positive way of saying this is that those who are not afraid of making mistakes will learn the most. By their willingness or indifference to being wrong in a conversation they overcome the problems of accumulating unknown unknowns. Meanwhile others who fear embarrassment accept a higher level of ignorance.
The negative way of saying this is that the loudmouth in class is actually doing everyone a favor.
It ties well into this article, as in the study alcohol is being used as a medium to decrease self-awareness. There could be more to this theory. For instance it possible that alcohol is accelerating the formation of new neural connections. But it wouldn't be needed to show a benefit towards learning.