I canned my smoked salmon last night in my pressure cooker at 11lb pressure for 110 min on my stove. Then I turned the stove off waiting for it to cool off and fell asleep. I woke up this morning with the canner lid still shut I opened it and everything looked good. It's been about 5 hours with lid still on and jars still in canner. Is that ok to do?
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.
When canned goods are allowed to remain in a hot environment for a long time (such as overnight) there is a small chance of "flat sour" developing. 5 hours actually seems to be on the low end so it is highly unlikely, however it is worth knowing.
Flat sour is NOT HARMFUL. However it has been describes as "a taste that makes you want to scrape your tongue to get rid of it".
In summary: very very small chance of "flat sour" which is not harmful, but incredibly gross tasting.