The 'it could have been acid' is a relevant question and comparison from the security/safety aspect - but I'm guessing not legally. If it had been acid, presumably it would have been a different charge because the damage is so much greater. Something like GBH?
Legally, I'm in the dark here. What else is included in common assault? I think this Farage assailant picked up criminal damage too.
Despite the comedy value, is it a crime? Would you press charges? And if you wanted to make a point, how else would you do it to avoid legal entanglements?
I'm...