NaNoWriMo, 3k, But in the 1st person

After an hour I realized I was writing in the first person from the point of view of one of the supporting actresses, instead of in the third person from the narrator’s PoV.  But it was really flowing so there was no stopping it.  So now there’s 3k more words than there were yesterday, but there’s going to be some real editing to do.  However, that’s a job for after the story is done.  That’s one of my rules.  Finish the first draft and then edit.  When I stop to edit, the story never gets done.  How often does this PoV shift happen to you?