Great job in your situation..you hit it on the head when you said you reacted instinctively to that situation.
When it comesto an attack with anykind of weapon..if you accept the fact that you might and probably will catch a shot of some tipe.you will do just fine.
I think that if you jam the attacker up, and do a host of atemi if not a technique you might win, by coming out of the situation alive.
As far as killing the attacker..i don't think that would be a good thing to try,unless you know a death touch technique...(lets remember legal ramifications too).
So yeah, i think that i choose to jam the attacker up...play my odds that way instead of backing and dodging and hoping that i won't get cut..