The two brothers kickpox, are just as guilty. They planned these scenarios (tales) to keep authorities guessing who murdered Natalee. All three are guilty and should pay with their lives.
I think you are right and it just emphasises the importance of the police negligence in the early stages of this investigation.
The quiet brother, Deepak, may prove to be the weakest link. If the cops are doing the interrogs right, they should get that kid to break and tell all.