[Toroi]

https://sampwiki.blast.hk/wiki/OnPlayerTakeDamage

Quote:

Return Values: 1 - Callback will not be called in other filterscripts. 0 - Allows this callback to be called in other filterscripts. It is always called first in filterscripts so returning 1 there blocks other filterscripts from seeing it

You're using the wrong callback, use OnPlayerWeaponShot instead for this to work out.