Probably he felt so badass and confident from the previous stabsNJ on the stabs, but why did you never cloak? I would have just noped out of there and left that bat scout.

constantly switching your weapons from ambassador to knife doesn't make you look cool >->
Tiny Dark! Too bad I dont like spies after last night HAHAHA
You need to keep you gun out more than your knife. That demo you could've headshotted and killed.That and you could've just tried for a headshot on other things far away instead of lurking behind them and potentially killed by something else.
So you'd seriously face a demo flinging pipes at you when you could run behind him and get the stab?
If you know where most of the enemy is, I think he did the right thing.
There just were ample opportunities to whip out a gun and shoot things. The demo wasn't even at full health anymore after the first bomb he lobbed. He could've potentially been killed with one headshot.