Preventing new replies in closed threads

[Serpius]

When a moderator closes a thread, most users will see a prominent Thread Closed label, with a padlock icon, and they will be prevented from posting new replies. That, of course, is exactly how it should be.

But other moderators don't see the Thread Closed label, and are free to make further posts to the thread.

Is there any way of changing that? So, when a moderator arrives at a closed thread, it looks and behaves just as it would to an ordinary user?

If that's not possible (or if it's very difficult), can I at least display some sort of warning or message to inform the moderator that the thread is closed?

I've looked at what I think are the relevant templates, but I'm having difficulty working out how they work.

Thanks in advance.

Mike

You may have already looked at this, but it's worth double checking this in your AdminCP.

You can do this as a group or as per user. 
If you only have one moderator, then, it's best to do it individually. 
But, if you have a group moderating a forum, then it's best to do User Group permissions.