I've been led to a store manager's house, but not for a truly major chain like Best Buy ... it was a Panera Bread 'business' address - evidently the home of the franchise owner culled from a full list of addresses for that chain.
As to the latter, there's a very good chance that your TomTom did what all of these devices do .. tried to put you as close as possible to a location ON a street. There's some chance that the Lawrence Expwy point was actually the closest point on-road to your destination. Your TomTom is not familiar with the layout of most parking lots.
I'd be curious to know the specifics of your search in both cases to see how they might be explained.
The units do some strange things at times. Some can be explained and some not. I am always amused when I am delayed on an overpass and tt cannot determine on which level I actually am sitting.
I get the 'straight' duh left at exit....turn around as soon as possible....... I think an "I am lost" possibility is not programmed into the units.