No, they'll offer you a phone number where you can get "distressed passenger" rates. I don't believe these rates are especially cheap but they may be available when other reasonable rates are exhausted.

In North America you only get hotel room vouchers if there's a mechanical problem or other problem in the airline's control.

I don't understand the "blame the victim" mentality here. Two connections at major airports is hardly an unusual itinerary. The pax were in a situation where AC had enough time to resolve it and failed to.

The transfer desk could have called the help desk themselves and asked them to reticket, or they could have rung the customer service agents and handed the phone to the pax instead of telling them to go landside to speak to them. They could even have rung the station manager and asked for advice. Instead they just washed their hands of it.

All that said, going landside doesn't really cost that much time in YUL. Time might have been running short even if they had dealt with it over the phone at the transfer desk. I've accidentally gone landside at YUL (funny story, but another time) and had plenty of time to go back upstairs to security and go back in again and the whole thing took 15 minutes. Tracking down AC customer service and LH checkin would start ticking away the precious minutes though.