I have found myself thinking about AM's testimony regarding the conversation in the kitchen when DM and MS showed up on the evening of May 5. This was after the IT test drive. Didn't AM say that DM said that they didn't steal the truck because MS was sick. And that he said it in front of MS. (I think this was where MS was reported to have eventually said he was hungover).
I've been wondering if they had the plan all ready to go and while they were in the car with IT, MS didn't do whatever it was he was supposed to do (hence the look exchanged between them and the change in atmosphere in the car, as reported by IT). So, then I picture the drive back to Maplegate, with DM and MS in the Yukon. Was DM angry that MS did not follow the plan? Did he call him a baby, a chicken, a coward? Did MS protest, no, I was just feeling sick, so I didn't go ahead. Then at Maplegate, DM would report to AM that they didn't steal the truck because MS was sick - calling out his story?
Just speculation on my part. MOO