A short summary of the movie says:
"In the aftermath of the accident, the girl begins to hallucinate
and believes terrifying strangers are following her, putting into
question as to whether the images are from a concussion or a newly
found gift of second sight, both of which might be connected to the
church." (indeed, the story involves an ancient legend dating back
to Christ's crucifixion)."
I think it is most likely not true and was probably part of the
storyline rather than a real event. 
