Sorry for another long post...
If they did do a loop on Book Rd, and assuming MS's story is otherwise true, is it possible that that is where TB was shot by DM? I'll try not to speculate too much, but hear me out: With TB sitting in the passenger seat to offer directions, they should've had a general idea of where they were going, so it mustn't have been a mistake to drive down Book Rd originally. What prompted them to then turn around and loop back? Wouldn't it seem odd if DM said to TB, "Oh, we've driven down this road far enough, let's turn around and go back to Trinity and then drive north from there, maybe we'll take some back roads to Brantford." Whatever transpired, the scenario does raise an important question: how far did TB go before he realized something was up?
If TB was shot by DM along Book Rd, then MS's allusions to it happening in Brantford are wrong. At least, that's how I interpreted MS's story of the swerve on the road just before pulling over in front of Bobcat, the putting of the gun back in the satchel, the crazy look on DM's face, the remark "I'm taking this truck", etc. I sensed an air of recency in this evidence. I could be wrong, of course.
If TB was not shot in Ancaster, then how did DM single-handedly keep him confined in the truck all the way to Brantford -- did he hold a gun on him all the way along, while driving at the same time? If there was no confinement (i.e. no holding at gunpoint) and TB was totally complicit in going on a test drive to Brantford, wouldn't it reasonable for him to text his wife, "Hey babe I'm gonna drive to Brantford with these guys so I'm gonna be home a bit later. Don't worry though, they've got their own vehicle following behind so I'll just drive back home on my own." TB didn't even check FB or anything on his phone; it didn't ping off any towers until around 10pm.
Any of these scenarios are possible, but I do not believe any of them are likely. The 10 minute problem is significant and should not be dismissed. In my view there is only one scenario that fits the evidence within a strong probability, and that is where DM and MS took TB on a test drive, one or both of them shot him, and then they came back to get the Yukon. JMO.