Canned smoked salmon
That's fine.

During canning, the increased pressure raised the boiling point of the water inside and sterilized the interior of the canner. As the canner cools and the pressure falls the bottles seal themselves. Once they are sterilized and sealed they are shelf stable if nothing breaks the seal.

Leaving the sealing bottles in the canner to cool overnight is not unsafe- it might make them a little harder to clean though.