Why do I get flashed when there is a flash behind me?

If you get flashed in your back or try to flash around a corner and you throw the flash behind you, you will be flashed, not for the full duration, but enough to make that play useless.

You should be rewarded if you manage to quickly turn away and flick back at the enemy and be able to still win the aim duel.

That requires a lot of skill to do especially to kill the enemy after the 180 degree turn.

if you can do that, you should be rewarded with an aim duel and not with a 600ms blindness.

It should be like in cs when you self-popflash in your back around a corner.