Sterilisation usually is done for longer than pressure cooking. The process will still be pretty bad for bacteria, partly depending on how many solid pieces there are in the cooker. After cooling off, the cooker is no longer sealed: the cooker I know has one valve that closes only after a short time of boiling in order to replace air with steam. This valve will be open again after cooling off.
However, the amount of air exchange through that hole will be small, so both processes driven by oxygen and contamination with mold spores will happen at a significantly lower rate than usual.
I would expect botulism bacteria not to survive pressure cooking, and new infections will only arrive with new air so I consider the anaerobic environment required for them to be not there.
Mold can either take hold or not. If it does, it will be from the surface and relevant contamination should be visible.
Other processes only driven by oxygen will turn into discoloration and/or bad smell and/or acidification (which may not be dangerous but usually spells the end of something tasting well).
In short: if it looks ok and smells ok and the cooker was as closed as it will be after depressurisation, my personal "don't waste good food" reflexes would likely prevail, but I'd not hide history and my personal judgment about it from others who possibly might eat from it.