Well, I can tell you from knowing some of the people involved in the case with KCPD that there wouldn't be any comparison to the detectives in the Michael Crowe case. As well, I sure don't consider DB and JI to be in any way comparable to 14 year old Michael Crowe.
I do agree with you that the questioning would be interesting to see, but if DB's inconsistencies and hinkiness on TV interviews are not enough to convince you that something is just not right here, I don't know that seeing them on a police interview would. Not trying to be snarky here, just saying that LE's job is to be tough on the most obvious people to have committed a crime. Innocent people might not like it, but they usually know that this is what has to happen to clear them AND to help find the missing child/whatever. DB admitted to watching these cases, so she knows very clearly that this is the procedure. She also knows that if LE smells something, they are not going to let it go. They smelled something in this case.