Autoplay after reload

Now this is what i think is really strange I don't know if this qualifies as a technical question, but it's not exactly a hardware problem.

I played a great game of Civilization 5 on LAN with my brother in law. He was Alexander and I played as Elisabeth. I wanted to continue playing it in singleplayer afterwards as we didn't have time to finish the game. I visited him a couple of weeks after the multiplayer game and logged in to Steam since I wanted to copy it to the cloud. When I loaded the game with England it immidiately turned into autoplay so I could just sit back and watch the AI taking over the control of Englang When I opened Steam on my own PC the next day the same problem occured.

I can't remember for sure, but maybe it was my brother in law who hosted the game originally. I've never heard of this before, and I was wondering how to solve this. If I make my brother in law load his game as Alexander and let me join, I believe I won't be able to save the game - or does he only have to leave the game to allow me to save it, and will this solve the autoplay-problem?

And BTW: Have any of you expierenced this or is it the first time you've heard of it.

I haven't heard of this problem before. If you post the save file somewhere I (and others) could see if we get the same problem.

OK, I've obviously already deleted the game, and when I visited my brother in law again, I opened it on the host computer, connected with my computer, and then left the game with the host computer. This time it worked the way it should.

The first time I somehow managed to load the game without the host computer, uploading it to Steam, and thereby I encountered the problem.