It just takes one unlucky time where the other person doesn’t subscribe to the idea of proportional response or has military training with muscle memory that takes over.
There is no thinking or musing whether they just want to slap you or I don’t know what. You don’t know your attacker and their intentions.
This is the real world. I don’t know why you would think this is some kind of stupid game to go around and slap people. It will cause problems.
Now the discussion is about how Facebook glasses are offensive and worn by murderous psychos who take creep shots of their neighbors.
I gave parent the term "adversarial fashion" as an answer to their query, they should look that up.