Hmm, I just retried and was also unable to reproduce it as previously discussed.
There is, however, a different scenario where its still a little problematic. This one requires another player to be connected to reproduce:
1. Start a headless server, using, for example:
mk/linux/megaglest --ini-path=mk/linux/ --data-path=mk/linux/ --verbose --headless-server-mode=vps,exit
2. Start a game client and connect to this server, using, for example:
mk/linux/megaglest --ini-path=mk/linux/ --data-path=mk/linux/ --verbose --connecthost=127.0.0.1
3. Using the client, which is controlling the headless server (as indicated by changing colors on the player number) change the map to Eight Gradient.
4. Still on the controlling client, change Control on Player 7 to Network.
5. Still on the controlling client, switch to Player 7.
6. Still on the controlling client, change Control on Player 3 to Network.
7. Start a second game client and connect to this server, using, for example:
mk/linux/megaglest --ini-path=mk/linux/ --data-path=mk/linux/ --verbose --connecthost=127.0.0.1
8. Make the second game client change into the slot of Player 3.
9. Back o the first game client, which is still controlling, swiftly (no pausing) switch the map to Conflict and wait 10 seconds.
10. You have lost control on the headless server to the second game client. You are, however, able to switch to a different slot where you automatically regain control.
I assume that's actually the scenario Pizza and I ran into, after all we are two.