Walking away when someone is trying to attack you is neither easy nor simple. De-escalation only works if they are willing to let it (or if you can confuse them enough, in some cases). Sometimes, they don't leave an option that's better than engaging with physical force.You are on my ignore list for good reason, but occasionally are so idiotic you cannot be ignored. He doesn't have a choice? He is not able to leave, not able to verbally de-escalate, he cannot not legally defend himself by striking pre-emptively and then leaving (which is not the same as offering to fight him, either legally, nor employs the same skill set as fighting). His first and only option as you see it is to invite the guy to participate in a fight.
Yes I understand consent, and the difference between fighting and self defence, and I understand the law as it pertains to civilian self protection from criminal violence. You would do well to do the same. And for the love of god never attempt to teach a self defence course to anyone anywhere. Ever.