I don't think I've ever accused the MCs of a crime. I have expressed amazement that the statements of the group keep changing and that very few people seem to think that this is odd. That seems to be changing now.
I have no direct knowledge of what happened, but you don't need a lie detector if someone contradicts themself repeatedly since you know that most or all of the versions must be lies.
I'm uncomfortable that it has been ok to suspect Murat and others (and now this guy) without any evidence at all, but not the people who were there and who have lied about exactly what they saw and did.
When others in their party have lied I'd expect the MCs to be furious with them, but they don't appear to be bothered by that. Wouldn't everyone be? There you are looking for your daughter and your 'friends' are making up clues to put you off the track.