An uncharacteristic scene from Invasion that puzzled me

Old stuff but I didn't mention it before.

So the Arrow part of Invasion arguably had very little involvement from other shows and is barely a crossover. But in that episode The Flash and Supergirl did have this moment.

Recall, there was this villainous cyborg woman that they needed something from. The fight was cool alright but in my opinion, very out of character for Kara and Barry.

So the Flash attacks first and gives her a beat down, but that's fair all good. Then, she is obvious defeated and unable to fight further, Kara shows up, knocks her across the room and Barry beats her again. Afterwards they high five.

What?

She was clearly incapacitated after Barry's first attack. Beating down someone harmless is something not even Oliver would do (well, maybe, because he "wanted to, and liked it" if you know what I mean). While the combo was cool as hell, I kept wondering how are Supergirl and The Flash suddenly so savage?

Maybe it's because the Arrow writers wrote that scene.