My wife had the same thing happen to hers on I-95 heading to Bike Week last year. With it being a brand new bike, she was inexperienced with the locking mechanism. She went out to the bike the night before leaving on the trip and (in the dark) took out her heated jacket. We "think" she must have hit the locking mechanism when pulling out the jacket and just didn't realize it. So.....at 75 mph, going down I-95......boom! There it went. Since then, she put on about 30,000 miles with no other issues. She now has a "procedure" when it comes to taking things in and out of the bag. She checks it to make sure they are in the locked position before closing the lid. It sounds like a pain, but really only takes about 5 extra seconds, and is totally worth it to not look in the rear view mirror and see her $1300 (ish) bag rolling down the interstate!! This happened to me a few years ago on 7 Mile Bridge headed to Key West.......it happens!!!