Well, Michael Lane isn't the Heretic.
I'm just confused as to which "Third Batman" she's referring to. Michael Lane, or his appearance in Batman #666. He still wasn't the Heretic. They're not even the same race.
Maybe it isn't that complicated to figure out. The satanic cult that killed Lane's family were actually Talia's men? She originally had Dr. Hurt create his own three Batmen, but for the third man, she put extra special care into?