@shiu sa more than likely she was already rather anemic due to being drained of blood every day so the increase of blood loss along with the pain of removing a rather important organ caused her brain to just shut off permanently. But it could just be story shenanigans
@shiu sa I GOOGLED THIS A WHILE BACK! If the tongue is cut off it tends to bleed a lot, so it can actually kill you via drowning. You could also bleed to death. It's displayed pretty unrealistically here, since as long as it's treated quickly you can live, like, you don't die instantly like is shown here. It'll take a few minutes at least I think?