in 'michael clayton' they have a dude carrying around a whole bag of baguettes!
Season's Greetings

I've not seen this movie yet, but were the grocery bags paper? Did she have one in each arm? I, too, have noticed the old 'French bread poking out the top of the grocery bag' scene in SO many films
and
TV shows. Just once, I'd love to see a loaf of Wonder Bread poking out the top of a white plastic grocery bag. If I had to walk home with my groceries, I certainly would put them in plastic rather than paper, to make them easier to carry. AND, if I had the fresh loaf of French bread, I would put IT in its own plastic bag, too, to keep it fresh and clean. I'd especially protect it if I was planning to put it in the trunk of
my
car!
Oh, and by the way not every home in San Francisco is on a hill, and not everyone has a cable car line passing their front door. In 'Sweet November' were the cable car bells ringing right outside someone's home? Almost as trite as the French bread!

If I remember correctly, in an interview Jason Isaacs says that he likes Toronto and "San Francisco" because they "feel" like European cities
Something like thatmore so than other US cities
"I know a little bit 'bout alot of things"

SF has been called a most European city (often by Europeans). It also has a huge artisanal bakery movement. So bread in their paper bags w/o plastic wrappers? totally plausible. I won't contest your observation of it being a visual cliche.