I assume that's enabled by accident, and not a conscious design choice?
It could prevent abuse of the system, but also open people trying to help the community up to abuse if they can't flag anonymously. I wonder if reporting is anonymous...
I can't see any sign of the post being reported. Did you report it? 😆
IMO, anonymity of the flagging system leads to abuse or weaponization of page functions. At the very least, community mods should keep a watchful eye for users who abuse the flag system or are flagging things inappropriately. Granted, that might take a lot of work.