Is anything in food really quick death like in the movies? Seems a taster would only give warning of impending doom too late. Maybe there is someone who can detect obvious off tastes. I have heard the the WH kitchen shops at random so the food stuffs can't be messed with, this for all presidents.
Or how about a[size=78%] taster finding things OK, then letting the fish sit for 6 hours, and then seeing what it does?[/size]