Technically it is saved. You can pull the save from the SPI chip using that savegame tool posted on 3dbrew. It's a bit complicated, but if you really needed that save, you can get it. BUT DO NOT LOAD ANOTHER GAME BEFORE YOU DO! Otherwise it is wiped
So if the 3DS crashes and the save is in the SPI chip, then if we immediately run the same game again and exit normally, then will the original save get written?