Map play very important role in this game and Cartographers may be far away from green spot. An icon of map drop will save players from seaching for map (They do not need to run back if there is no map drop)
I have never seen one instance of cartographer being far away from green dot on map, the only way that could happen is if you lure/kite him.
Cartographer will always drop his map on the spot where he dies.
In all my time of playing, I have only ever experienced no map dropped from cartographer 4 times in total. (All those 4 times have always been on the lower 200 floors, so no problem buying another map and running it)