And your 'tap on the shoulder' analogy is pretty flawed too. That's assault and likely to result in a physical response.
Not in my country, dear. We're not that fragile around here, to consider a tap on the shoulder as "assault". I mean, seriously, how fucked up IS that?
Bottom line: this guy is being a dick.
I'm not saying he isn't. I'm just saying is not really that big of a deal.