The “reporter” got it wrong - the guy didn’t swing an umbrella at the woman. He held the umbrella in his right hand and swung with his left. It looked like a clumsy or drunk knife attack to me.
Clumsy or drunk doesn't matter. Attack me with a knife, get shot. Simple. Don't wanna get shot? Don't attack me.
BTW, the woman appeared to me to be projecting a major "Don't Fsck With Me" attitude even before the apparent perpetrator started perpetrating.