When a unit is killed in Arma 3, if that unit has a primary or secondary weapon, it will be dropped in a WeaponHolderSimulated which has its inventory linked with the unit's inventory. Opening the inventory of the WeaponHolderSimulated which only contains the weapon, will show the inventory of the entire unit, and likewise opening the inventory of the unit will also show the weapon, even though these are separate inventories, they are linked.

As stated, in the Title, the "Take" Eventhandler does not fire for corpses when objects taken from linked WeaponHolderSimulated (and vice versa). I do not believe this is a bug, but it is missing functionality that would be useful to have.