If you don't lock the doors, don't be surprised it the insurance company denies the claim. Of course, they'd have to prove it wasn't locked. One thing we always try to do is find a restaurant where we can watch the rig through the window of the establishment.
I think the thing that would bother me the most from this break in was the loss of the pictures on the camera's storage card. It's a good reminder to upload your pictures to a cloud server anytime you get to a spot with reliable wifi. At least they would still have there photographic memories.
Thank goodness the thieves didn't hurt or steal the doggie.