I do really like the idea of the revive time when you use defibrillators as EMS.
But! The revive timer should be like 10-30 seconds. Not like it is now when you revive someone and they die again shortly(example in a fire), then they can't be revived again.
I came to think of it because i was playing EMS and there was a fire in a house. I asked the fireman to make a way through the fire so i could revive a dying person inside. He did so, and i had the person revived, but as we all know, the fire spreads.. Almost out of the door a "fire" caught the person i had revived, and he died again, and he couldn't be revived again!