Another example of a situation like this is when multiple users make observations of the same organism at the same time (“shared observations”). There’s a feature request for that and I think the discussion mentions some of your situations as well: https://forum.inaturalist.org/t/share-observations-between-users/337
The staff have it marked as “very challenging” I think because it would require some rethinking of the logic behind what defines an “observation” on iNaturalist.