The whole "what were there intentions" doesn't really matter because you can leave a car in another country. They'd travelled the US and Canada was likely their last destination
It’s not like the EU. You can’t just take a rental car into Canada without having cleared it with the company in question. So they lied to the rental company, because if they had cleared the route, they’d have the proper paperwork. This is the reason Canada refused them entry in the first place.
If you believe that they would leave for the UK from Canada, then either they were going to abandon the car in Canada or they lied about their route to the rental car agency. That doesn’t reflect well on them.
Their own actions caused them to be refused entry to Canada but you say THEY should have been deported and slapped with a ten year ban. Why would SHE when she had done nothing wrong? Why do you think she should cop a ten year ban and forced removal when she had valid paperwork to be there
If you abuse the spirit of a B2 visa (ie they suspect you intend to reside in America) then they have valid grounds to detain and deport you. The small detail that they did not have permission to take the rental car to Canada is suspicious, in this light.
They were on an 8 week holiday. Canada was their last destination
So why didn’t she take the ESTA instead of going through all the trouble of a B2 visa?
There was absolutely no reason to believe she was anything but a tourist. A B2 visa is not just handed out for fun, lol. She clearly fulfilled the conditions of having one. She may have applied for it believing that her husband was going to continue working in the US. Who knows? Doesn't change the fact that there were no grounds to treat her that way. You can speculate on what she 'might' have done but, she hadn't done anything wrong
You can technically stay within the conditions of a B2 visa by crossing the border into Canada or Mexico every six months or so, but it is not in the spirit of the visa and they will rightfully suspect you of intending to reside in the US. And CBP will be aware that people abuse this visa in this exact manner.
You are also focused on him being in the US illegally but that is a common tactic. What was his status? He had been on a valid work permit. At some point he had tried to get a green card I believe. Didn't happen so, at some point, I assume his visa ran out or he was not fulfilling the conditions of his work one. He was leaving the country and would not have been able to reenter obviously. Applying intentions to justify disproportionate treatment is still just making stuff up
We don’t know anything about her husband’s status other than whatever he entered on had expired—and this omission is curious. Did he overstay a tourist visa? Who sponsored him? Was she ever in America before? Is this the first time she entered on a B2 visa?
Honestly a lot of unanswered questions here. They are curiously silent on what exactly Bill was doing in America, why they were living separately, why she went through the hassle of a B2 instead of just going ESTA (particularly since she was only going for 8 weeks?)
Again, these are not normal tourists.