This recent thread has a very similar question and answers:
https://forum.inaturalist.org/t/live-seafood-as-observations/45011
To paraphrase/half-quote my answer there:
Yes, I think it’s possible to add these observations, BUT observations are supposed to be the observer’s interaction with some natural organism.
If they did not encounter the organism in the location where it was caught (which seems the case), but at the restaurant, the observation should be located at the restaurant and marked as captive. An observation at the catch location would really be of the unknown fisherperson’s encounter with the oyster, not the observer’s (and the ability to determine catch location is fraught).
If I encountered an observation of a cooked organism at a restaurant with a location not at a restaurant, I would leave a comment and probably give a downvote for “Location is accurate” in the DQA depending on response.
On the other hand, if someone harvested the organism themselves, and is taking a picture later, then adding the time/location of the harvest would be ok.
So it’s probably ok to do this rarely, but I wouldn’t recommend making many of these.