This may have been extremely obvious or not. So I did some testing. If the person eats poison fish steak in tram nuthin happens. Go to Fel and person gets poisoned and is able to give murder count. My char was to full to eat so the fish steak remained in his pack but still got poisoned.
The poison is only good for one use, meaning he tried to eat the same fish steak again with no affect. Now I am wondering what happens if I give my char counts and he becomes red while in tram !