https://www.amazon.com/Chemical-Warfare-Secrets-Almost-Forgo... - Chemical Warfare Secrets Almost Forgotten: A Personal Story of Medical Testing of Army Volunteers, by James S. Ketchum MD
Jong Nam felt uneasy after being sprayed and went to KLIA clinic. As his condition worsen, he's transferred to Putrajaya hospital which is 30min away from KLIA.
He was pronounced dead upon arrival at the hospital. I would say 30min to 1 hour for the nerve agent to actually kill someone.
Sorry I don't have source. Just watched the news few days ago on Malaysian TV.
I don't know anything about nerve gas, but do know about a couple topics that I suspect would trigger the same people, and it creeps me out that people become suspicious about someone for simply knowing something.
Probably worth keeping in mind that not a few people put cryptography in the same "military secrets" bucket.
It's one of the reasons I leave this site every day feeling wonderfully inadequate :)
In reality atropine and pralidoxime(antidote sorta) administration would have most likely saved him, but it would be very unlikely for a medical professional to deduce that the threat was cholinesterase inhibition(nerve agent poisoning).
To use a very clumsy analogy, imagine nerve agents like VX are slamming on the brakes of your body. Atropine makes your body less sensitive to the effect of "brakes". 2-PAM takes the foot off the brake.
Wouldn't have hurt, though...