There are Js calls to get current user. The current user would be compared to the user who flagged the post and the owner of the post that was flagged.
If 2 of the conditions match as true. Then the buttons other than defer post are dry to display none in the review que. With a text banner starting You are not permitted to review this flag
Dan
The Hide topics from blocked/muted users would use a similar logic but compared topic owner user if with current user’s ignore list.