I don't think BBM has any more mistakes than any other movie. A bigger budget isn't a guarantee of anything.
Geez, just go to Amazon and look up 'Pirates of the Carribbean' and just peruse the enormous list of goofs and gaffs and historical anachronisms present.
None of which detracted from my enjoyment of the movie.
I just watched 'Cast Away' with Tom Hanks, a Zemeckis directed film. on TV and there are scenes where it's painfully obvious that a single scene is filmed during differnt times of the day because of shadow and location of the sun. They can't argue that they were a low budget film and couldn't afford to reshoot for continuity's sake. That happens in movies from "Lethal Weapon' to "Glory" and probably hundreds of others. It normally just comes down to the fact that the director like the way the actor looked in this scene in this light better than another.
As for the same cars being parked across the street from Aguirre's trailer a year later when Jack goes back to look for a job...well, I guess my car is a goof too. I've been working for my company for years and I park in the same spot every day from year to year, too.
I agree with JP, the outer row of peanut jars fell, not the inner ones, so that's not a goof.