LE's statement that DM's gf may be a witness and the driver of the second vehicle may have been female puts a spin on things
The participants in the crime might have been DM, DM's gf, and the younger, shorter, smaller man in his early 20's, suspect #2
In this scenario DM sounds like the leader, and certainly the biggest of the 3 (at over 6 feet) and probably the one who overtook TB
...but he sure is stupid to have so much evidence tagged to him
if DM's gf was the second driver, I think they stopped in the brantford business park to rearrange passengers and split up, and dump TB's phone
It would have been incredibly risky to have two men and a body in a hot truck, so I think one of the men went in the SUV with the body and the other flew solo in the hot truck