Might it have to do with the speed the page is edited / published?
It seems like you are capturing events in Initailization module. That triggers auto save (after content update, when you use Save action) and then asking you to publish that changes. Can you search in Initialization Modules for Save Action.
Most probably the event will be PublishedContent. It occures when the item is published.
Try a global search in your solution and look into results for Initialization Modules.
Yes, it seems like you published the page before it saved in the database. I think it should not display the publish icon until is completely saved the data in database.
So I think you can report this to Episerver.
Does it only happen when you try to publish immediately after adding an image using drag-and-drop?