killmode stun not working?

[Namic]

Rasoun joins the battle!
You say, OOC, 'I am'
Your crush deftly shreds a metal dummy's chest.
A metal dummy is DESTROYED!
As the dummy falls, its armour crumbles to dust.
You blink.
Your killmode is: stun
You say, OOC, 'You blink.'

Helping a young mage in the Halls of Wonder. The two helpers myself and Rasoun are on killmode stun and we are killing the dummies when we should just stun them.

[Althasizor]

Being dummies, they are 'DESTROYED' when they take enough damage. They cannot be stunned or killed because they aren't alive.