Tapes are indisputable evidence...just like Howard's famed videos of a sloshed, drugged woman who he was "trying to help" and "was in love with".
I think Anna turned on him when at some point. Was there a picture of Howard, Anna, Daniel and the baby in the hospital or was it to just show that Daniel was alive and well that night.....and the pictures couldn't wait until morning. Howard's just an amazing "creator of indisputable evidence".
How ironic. Poetic justice.