Possible Server Bug: "Ghost" Players Consuming Slots?

I saw this on "Johnny5.net #2" earlier.

In the server browser, it listed the max players as "12" and the remaining open slots as "1."

However, when I joined the game, there were only 9 players total. It was a 5v4 with 5 players on Hotshots, and 4 on Icemen. It stayed like this for 4 rounds..5v4, with the total player count never exceeding 9. When I eventually disconnected, the "open" slot number was again listed as "1 of 12" even though there were only 8 people on the server.

Is this some sort of issue with server-set player numbers not displaying the "max" properly in the server browser, or is it actually a bug with the server software?

Has anyone seen something similar?

In the past two-ish weeks I've been playing, this is all I've seen. Servers with decent ping and five slots open are filled to capacity. Why are these five players in the server not playing?

Ghost slots.