IMO SS knew about the truck theft and was helping cover it up. Given how closely involved he was with DM and his vehicles, he would have certainly known about DM's desire to get a diesel truck.
It was a huge deal for them, and the minute SS saw the truck in the hangar he would have been all over it checking it out. Many questions would have instantly popped into his head:
- Why are there no front seats?
- Why is it sitting on a tarp?
- Why is the carpet cut out and sitting underneath the truck?
- Wait, are those... blood stains on the carpet?
- Oh god... those are definitely blood stains on the dashboard...
He said DM told him he bought the truck in Kitchener and drove it to the hangar sitting on a pail. Hm, that's a perfectly legit answer, I guess I won't ask any more questions. When the Crown asked him about the windshield removal kit, he claimed he tried to use it on the
red Dodge Ram, not the black one sitting in the hangar. Sure, SS, sounds like you're just covering your own arse. He took a fit on AJ and told him to keep his mouth shut. And despite his testimony, IMO SS did alert DM about AJ's call to Crimestoppers. I don't see a better explanation as to why DM suddenly moved the truck to his mom's house and tried to hide a bunch of other evidence on May 9.
IMO SS took a "don't ask, don't tell" position on TB's murder too, and likely knew or had a strong suspicion that the incinerator was used. AJ probably agrees and that's why they haven't talked in 3 years.