I was curious about the scenario you presented and looked up whether or not a case such as this occurred in the past. And I found a case similar to the situation you imagined. Links:
https://www.sootoday.com/local-news/19-year-old-says-not-a-drop-since-car-jacking-181388 and
http://www.saultstar.com/2015/06/23/carjacking-nets-house-arrest.
Last year, 19 year-old Nicholas Burns was convicted of forcible confinement, assault, and two other counts for having threatened a woman in her car with bodily harm while drunk in Sault Ste. Marie:
"Burns got into her car and demanded she drive him home. Once in the car he started to touch her arm, and was told to stop. When she tried to get him to leave, Burns yelled at her, and said he didnt trust her. He then said that he would smash her head against the wheel and pulled her hair, Crown prosecutor Mary Pascuzzi said. Burns then told the victim to get out of the vehicle. She ran away and called the police."
Granted, in this case, Burns ordered the woman to drive him home, told her to leave the car when she wouldn't, and had voluntarily pleaded guilty to all charges. Even so, he acknowledged the conviction and served his sentence (because he was truly remorseful, thought he would lose the case, or wanted to lessen his sentence). So while the jury in the TB case may rule differently, there have been unique circumstances such as I've described here that urged the Crown to confidently pursue the forcible confinement charge and actually secure it.
But again, perhaps we'll never know what happened in TB's truck and the jury will have to determine the most accurate interpretation of events as they see it. I'm not sure which explanation might offer the Bosma family better closure, and my heart goes out to them in this regard.
On a final note, I didn't sense that sleuths here thought forcible confinement was a given, only that they were persuaded one way or the other with the evidence they've reviewed. I believe the Crown will still have to prove its case before the jury, as I think they've tried their best to do. But we've still more to hear from them and I want to see how they'll proceed from here.