[... A bit suspicious, isn't this? But if there's a conflict between Servants going on, it's not in Jeanne's place to put a stop to it. She'll only do so if innocent people get caught in the crossfire.]

Hm, a good question. The administrators work in very mysterious ways, from what I have been able to gather... if they have the great power to bring a person back from the dead, than I don't think it's much of a stretch to assume that they must have some way to stop us from returning to the Throne of Heroes upon our death.