Through rose tinted glasses more than half a century old, I have only fond memories of board rubbers being thrown. They never hit me but there were a few near misses.
The only teacher at my school who threw board rubbers was Taffy Williams, the Latin teacher. He was an alcoholic and war hero. He always taught in an academic gown and was also capable of making Latin an enthralling subject. I bitterly regretted having to give up studying this so called "dead language" which later in life would turn out to be more useful than my pathetic attempts to master French.
He also ran the house rugby team and spent five years saying to me "Your name is first on the team sheet, Number 8." This was a bold move as all the rest of my school age rugby was spent as a centre or full back, but it worked well. He would have been amused to know that more than twenty years after leaving school I had evolved into playing tight head prop for London Scottish (despite not having a drop of Scottish blood in my body).
.