I agree that it is only information coming from Ronald to Tim and MN. However, it does appear to me that Tim believed him and believed Teresa enough to get Misty down there to take the tests. IMO, I think he would have mentioned that in the past few days if Ronald had requested it or had refused such a request.
I listened to the audio again. He is angry with the whole clan because he feels he is being attacked and called a liar while they pretend to support Misty (which they are doing). It doesn't mean he doesn't believe them about Haleigh going missing, but he is saying they are not telling the truth about how this whole incident of the tests came about and who they suspect which is Misty, imo.
I can't wait to hear more in the next few days and sorry if I get excited when we get bits and pieces to discuss.