Queen Buzz,
I think this is just a galley gossip story. A pilot is not qualified to call/pronounce/certify death. The Captain can provide advice to the crew if s/he thinks that continuing would put them n danger (for example, imminent landing) however that is the extent of their input aside from if they are diverting or not.
EK have a procedure which outlines when/if to cease CPR. It is quite possible if CPR is being performed using the AED, if the AED keeps advising to shock, then CPR could well go for some time as the crew are not permitted to stop if the AED says to keep going.
Only a doctor can pronounce death; it must then be certified when landing at either a diversion or the intended port. Medlink can advise whether to continue CPR, and there are several other criteria which when met means that CPR can be stopped. I would hazard a guess that most airlines have a similar procedure in place.
Leave would be given but I doubt it would be that long for ALL of the crew, maybe one or two if they had a very adverse reaction; that would be decided by the company medical staff and/or the EAP staff.