I recently experimented with a hashtag that would cause replies to become moderated, but when such replies do come in, there is no indication that the reason why the message is moderated is due to a hashtag. This means that unless all moderators know which hashtags cause messages to become moderated, some eager moderator is bound to approve a message if it complies with the usual requirements for approval (e.g. if the message appears to be on-topic, etc.). In my use-case, I wanted to prevent unnecessary replies about a certain topic, but the replies are otherwise perfectly on-topic and only moderators who are aware of the hashtag (and watch closely for hashtags) would have realised that the message should have been deleted, not accepted.
So, please, when a message is pending, let there be a notice on the screen (and in the e-mail) telling the moderator WHY the message is pending.