I read that Shelly stated this earlier, and I wrote my post as such last night. Later, someone indicated it was her coworker from Progress Energy who reported Michelle's version of being unbuckled. Ergo, I may be incorrect in stating Shelly Schaad testified to this. Someone testified that Michelle told them she was unbuckled. Also, it was reported that Michelle did not speak to the trooper, only Jason did.
In the context of the accident at that very moment it did not appear suspicious. Now we know that the life insurance had been boosted to $1 million, that Cassidy was purposely left behind for a short trip to get coffee. We know that weeks before her murder, Michelle's life insurance was boosted again, and her being dead was worth up to $4 million.
Draw your own conclusions.