I thought these pictures (918298, 907398) were DNP, and they were, so I flagged them. But later I noticed that they were uploaded by the artist, which nullifies the DNP. Can the flag be removed before someone accidentally removes the picture without checking the comments?

im fairly sure that they wont get removed. but if an admin removes the images, you can send a message to the admin who removed them and explain what happened. images can be easily undeleted.