When flagging a review, include the option to add an image, in case if it's more simple or easier for the store owner or another buyer to explain why the review was incorrect through an image.

As an example, this gives anybody the ability to provide a screenshot of the conversation between them and the reviewer, where the reviewer admits they were wrong but is belligerent and can't be bothered to correct or delete the review.

For the example above the person flagging the review in question could be because another buyer ended up asking the reviewer because of the vague review or the store owner trying to address the issue or possibly even the reviewer friend in which the reviewer is found to be in the wrong.

Though there are other ways to use the image upload other then just to show a conversation from a hostile buyer. It could be used to show that this person is a fresh account that has caused issues with others or that its a competitors alt account or that the reviewer is now happy but for whatever reason (such as - can't be bothered) is unable to delete / fix said review.

I could give several more examples but I'm not going to cycle through all of them. Plus sometimes a picture is more evidence than words and can be more accurate than you're able to describe if you're limited on vocabulary.

Oh and if this is implemented, it would be best to allow people to upload more than just one image, while limiting the file type to keep the file size small.

Also if possible - allow the user to update their flag if other pertinent information needs to be added.