I'm thinking TB would have been immediately suspicious about a story by DM to MS that their mysterious "friend" couldn't find a Tim Hortons and decided to park in that field area to wait for them to meet up. According to SB, TB was already feeling uncertain about going with the potential "buyers" of his truck, so I think he'd have been very alert to suspicious stories or behaviours, IMO.
DM or MS would had to have received a call or text from someone in TB's presence for such a story to be convincing, IMO. From the moment they met TB until MS got out of TB's Ram, TB was in the presence of both DM and MS, so the story MS is spinning today doesn't add up for me.
Didn't MM call or message MS while on the test drive? Perhaps it was part of the plan to have someone call MS or DM around 9:15 and they'd use that call or text to convince TB that the lost "friend" had called them? I think there was a plan for the truck theft and I'm not convinced that MS wasn't aware of a plan by DM to murder TB, but that's just my gut feeling in response to MS's testimony so far today.
All MOO.