In the case of Daniel, there were two people present, Howard and Anna.
You can be damn sure that Howard convinced Anna that she was in some way guilty of contributing to Daniel's death and that they might take the baby away from her. She consequently had to protect Howard to protect herself.
Marriage, fatherhood, the "I hate Mom" video AND THE LATE AT NIGHT VIDEO OF ANNA, BABY AND DANIEL (all happy and healthy) were part of the protections she gave him whether she knew it or not. (Do you REALLY think that Anna knew Bahama Law?)
So, Howard wasn't lying about Anna's "WISHES" based on the plan that she DID know....She simply didn't know the REAL plan.
There is definitely motive and opportunity.