Sorry, but what the fuck was he thinking walking up and putting his arm on/around a stranger? He stupidly initiated that physical interaction. Now, I didn't see any effort by the knife wielder to try to separate/distance himself before the attack, which makes the knife use ostensibly disproportionate, but it would be pretty easy in this case to state that he felt in fear/was defending himself.

Sorry, but what the fuck was he thinking walking up and putting his arm on/around a stranger? He stupidly initiated that physical interaction. Now, I didn't see any effort by the knife wielder to try to separate/distance himself before the attack, but makes the knife use ostensibly disproportionate, but it would be pretty easy in this case to state that he felt in fear/was defending himself.