Weird thing I saw one time living Montreal

I'm not sure where to put this but it was a very strange experience and not entirely sure what was going on, but had my guesses.  

When growing up, I'd often visit my elderly grandmother in Montreal with my mom driving.  My mom was originally from Montreal and we'd often make the commute on weekends from Ottawa.  One day, while traversing on our return home from Montreal, we went through residential neighborhood to take a short cut.  

We saw the strangest thing, a large van - non-descript - with smoke billowing out the back.  To add to the weird situation, there were two people, a man and a woman if I recall, running towards the back of the van, carrying a sofa to put inside 'the smoking van'.  

I don't know why my mom didn't stop, maybe it was instinctual that something wasn't quite right with the whole situation.

Afterwards, we thought perhaps it was fraud and that they were trying to claim damages by putting the van on fire and then damaging the sofa as nothing else really makes sense.

Any thoughts?  Not sure how long ago this was, but I think I was in my 20s at the time.