Saw a Mythbusters recently where they showed that a drug dog can not only smell weed stored in a glass jar, but deterrents, such as a female dog in heat or dog whistle are no match for a well-trained dog.
Now, there are a couple things to consider:
Was there residue on the outside of the jar from when the person was handling both the weed and the jar and that's what the dog smelled?
Was the show a fake so that it would be more like a deterrent for anyone looking for a good way to hide their stash?
I don't know how an odor could possibly leak through an airtight jar, so I would guess that there was resin-laced fingerprints on the outside of the jar.
With that being said, unless you thoroughly clean the outside of your jar every time you're into it, chances are the dog's going to pick it up.
I would run a carbon scrubber + ozonator for the most odor elimination if you have that much f a concern, but most importantly, do not ever give a reason for the cops to bring a dog to your house to begin with. Don't show your grow to your friends or family, don't sell it, and always be aware of your surroundings when you're smoking. Take everything you read on the internet with a huge grain of salt. People can say "I've been using this method for years and never got caught". Well, maybe that person just got lucky or doesn't live in an area where neighbors are bothered by it. Nothing beats good common sense. With good odor control you should be able to keep the smell from neighbors or people walking past your house. If they can't smell it then they won't have anything to all the cops about.
Oh yeah, don't take ANY advice if "so I've hurd" is attached to the statement..especially when it comes to something that can land you in jail.