The way IPToCountry works - at least at the moment - is prone to this kind of error, though it's not the fault of the developer.
Briefly, the UT server sends the IP address of every player in the server to a PHP script.
The PHP script opens a file. The file contains a list of IP address ranges, and the countries to which these IP addresses have been allocated. The PHP script sends a two character country code back to the UT server, and the SmartCTF HUD (or Nexgen, etc.) uses this code to select the country flag image to display for a particular player.
The problem is, deals are done between countries and institutions for blocks of IP addresses, and they change hands occasionally. When that happens, the entries in the file that the PHP script uses become out of date.
The best course of action would be to ask the server administrator to update their copy of the IP database file, which is available on the MaxMinds website, to the most recent version:
Since the server admin set up IPToCountry in the first place, they should be able to figure out what to do with this.