There's a phenomenon called "Groupthink" that can overcome Occams Razor.
It's the sociological fact that sometimes people will go along with a leader and march right into trouble. People might be aware that they are going wrong, and someone might be tempted to say "no," but out of loyalty they won't rock the boat. They want to belong to that little group. So the whole group follows the leader out on a limb in what they call a "risky shift" that they wouldn't take by themselves.
This happens many times in cases like this when family loyalty comes before right, wrong, or common sense.
What are clues that this is happening? The fact that the Phoebe D. went along with the story that she was at home even though she knew that wasn't true. The fact that some blogger is posting several versions of the story, and that Justin is the one who gave them to her.
I see Justin as the leader of the "risky shift." Ayla was his child. Everyone else involved is somehow connected to him or is taking their cues from him. No one is really thinking for themselves yet and speaking out because they know it will make the family angry, and they want that in-group because it's all they have.
http://www.psysr.org/about/pubs_resources/groupthink overview.htm
Janis has documented eight symptoms of groupthink:
1. Illusion of invulnerability Creates excessive optimism that encourages taking extreme risks.
(if people have gotten away with things in the past, then they have confidence in trying again under dire circumstances: hiding a body, lying to police, making up stories)
2. Collective rationalization Members discount warnings and do not reconsider their assumptions.
(They all must have good reasons for handling things this way, and meanwhile, no one is talking, everyone is lying, and they believe that's going to work for them)
3. Belief in inherent morality Members believe in the rightness of their cause and therefore ignore the ethical or moral consequences of their decisions.
(They thought Ayla would be better off with Justin because he thinks he is a superior parent and his family is morally superior. They still think they control what happens because Ayla belonged to them and it was their house - erroneous. It doesn't matter if drinking, drugs, or anything else was going on - they still know better than anyone what is "good for Ayla")
4. Stereotyped views of out-groups Negative views of enemy make effective responses to conflict seem unnecessary.
(Trista was the enemy, the police are the enemy, now the suspicious public is the enemy, while the family is above everyone else)
5. Direct pressure on dissenters Members are under pressure not to express arguments against any of the groups views.
(Again, no one is talking out of some type of fear, and maybe they are sworn to secrecy)
6. Self-censorship Doubts and deviations from the perceived group consensus are not expressed.
(Phoebe DiP stuck with her "at home" story even on National TV - couldn't break with the group)
7. Illusion of unanimity The majority view and judgments are assumed to be unanimous.
(This is the weak point - who will make a deal and break the vow of silence? Who is worried about custody of their own children? But Justin the leader probably still believes everyone is on board with the lies.)
8. Self-appointed mindguards Members protect the group and the leader from information that is problematic or contradictory to the groups cohesiveness, view, and/or decisions.
(This blogger friend of Justin's appointed herself spokesperson and writes that everything is fine, everyone in the family is on the same page, and nothing is wrong except that Ayla is gone and the public is too suspicious. She attacks any different theory as vicious, and thinks everyone should just accept that Ayla is living somewhere else where she is just fine, fine, fine. She's like the spokesperson for denial. )
