That is amazing and scary as well as rare, but not totally unheard of.
When I was very young my mom developed pneumonia and ended up in the hospital, where later she was pronounced dead. My grandmother was there at the time and was allowed to see my mom to say her last goodbyes. She pleaded with my mom telling her that she couldn't leave us yet, that her three children needed her and that she herself, was too old to give them what they needed in a mom. When my grandmother was overtaken by sobs, my mom sat up in the bed and it was grama's startled screams that brought the nurses and doctors scrambling back to the room.
Anyway, I think that the power of love is an incredible force.