I don't think that being beaten for speaking Gaelic at school was actually being anti Gaelic, what it was, was for being non conformist. I can remember children being beaten for not conforming, writing / doing school work with your left hand or having long hair or having your white school shirt not tucked in were common causes of being beaten if you were a serial offender while I was at school in the 60s and 70s.

Since I assume most of the teachers would have been outsider English / French speaking they would not have to tolerated being unable to understand what was being said.