Have you all heard of Occam's Razor? Basically it states that the explanation that makes the fewest assumptions is usually correct. No, it's not foolproof, but I also feel that many of these excuses being made for MTR are unreasonable. He drove the car. He drove past the school (repeatedly). He was with TLM. He lied to the police. He was there when a little girl was murdered.
I don't really buy the drug debt theory, so therefore I don't buy that TLM kidnapped her for that purpose. And let's face it, when a man is involved in a kidnapping of a child that is not his own, it's usually for sexual purposes.
So we can assume:
-MTR was an innocent dupe who had no idea what was going on until it was too late
-he had no idea why TLM really wanted to stop at the Home Depot (and why in Guelph? Isn't there one in Woodstock or at least London?)
-he was unaware of the social protocol that you just don't take a strange child in your car--or ANY child, without their parent's explicit permission.
-he was also unaware that driving said child far out of town went even further against the social protocol
-he was waiting in the parking lot of the retirement home because...there was too much traffic? Nobody seems to want to touch that one
-he drove out in the country just for the hell of it--again, with that strange child in his car
-he pulled into a VERY secluded spot just so that TLM could talk to Tori without him present
-he walked far enough away that not only could he not hear them talking, but he also couldn't hear or see TLM viciously murdering Tori with a hammer, using more force than was necessary to kill her
-he was also far enough away that he couldn't hear Tori screaming
-he didn't hear or see his trunk open for TLM to obtain the murder weapon and garbage bags
-he was terrified of her even though he was quite muscular at the time, and almost certainly stronger than her
-instead of backing away slowly from the murderous maniac, jumping in his car, locking the doors, and taking off without her, he helped her clean up this vicious murder of a child
-not only did he help her clean it up, but he also then drove her back to her town, dropped her off far from her own house (would you take that chance of ticking off a maniac by leaving her to walk home in shoes that didn't fit if you were afraid of her? I wouldn't), and then tried to help her disguise her identity
-he kept it all a secret and didn't help her family get closure even though he was simply an innocent dupe and didn't have anything more shameful than that to hide
-her blood was found in his car because...she had a nosebleed?
-he got rid of the seat because he suddenly decided, after participating in cleaning up a murder, that it would be a fine time to spruce up his car
-he had TLM discard chunks of the seat because...you got me with that one. The defenders seem to be ignoring that part.
No, that's too many assumptions for me to make. I think this case is a lot simpler than that.
We can also assume that he was abducted by aliens, his car seat was beamed up into their ship never to be seen again, and he was a victim of their mind control and that's why he did nothing, before or after. But is it reasonable? No.
And that's why I think it's unreasonable to keep trying to explain this all away. Taken together, it looks clear to me.