I think I understand what you mean (maybe, LOL, you are not dealing with an educated person so you have to kind of dumb things down ) By analytical or abstract, you are speaking of taking EVERYTHING into account, i.e. evidence, behaviors, statistics, actions, etc. and not JUST physical evidence (which would be concrete or simplistic thinking). As far as actions by LE, there are obviously some "clues" as to what they suspect, but to me, just not enough to be 100%. By the very nature of their job, they are going to suspect the parents. And who is to say they don't have tunnel vision? They are only human, after all, and just as infallible as the rest of us. This is not a disparagement of LE, just the way it is.
And I just don't see enough here to set this in my mind 100%. If LE came forward and said there was more than one dog hit, or some type of blood evidence, or something concrete with the phones, etc., then I would say "Ooooooh, d#$@!"
But anyways, what I am trying to say is, in regards to this thread topic, is that while the parents not speaking to media is bothersome to me, it is not enough to scream "They did it!" I have to see more in regards to concrete, physical evidence. And some may think that abduction is completely impossible, I can't rule it out.
And as far as a stall tactic, I guess I don't see the point. If law enforcement is building a case against these parents and they just need more time, then why would the defense be stalling? Seems like they would want LE to charge them right now before they have time to make a strong case against them.
JMO