The main issue is that I cant take away a teammates share map status, but can change the status of AI players. Is this an issue with anyone else?

I am in a 3 team map (Day 4) and I suspect one of my teammates is an alt because he grouped his units and has sent them at the 3rd team, leaving his whole country unprotected from attack from a team 2 player, and has not built anything. I gave him a map share agreement on day one and he accepted it on day 3, and cant take it away. I don't want him to be able to tip off the team 2 player who is attacking across the Mediterranean sea with no naval support and I have built 4 subs to stop his convoys. If I am wrong, this player will be useless to help me anyway because he could be taken out in a day by the opposing team.

I am reluctant to report him because the only evidence I have is circumstantial, I would prefer to just unshare the map. The fake account is not the problem for me, it is who ever he is giving his resources to and sharing the map info to that would be the real problem. Could that be investigated? Temped to set a spy on him to view last trades.

Evidence:
1: The players name begins with the letters FakeXXXXX X represents some numbers.
2. The player has never even built 1 unit or trained one unit after 4 days.
3. The player grouped all his units and sent them against the third team.
4. The player left his whole country open to attack from another team bordering
5. The player has not responded to my note of astonishment that he is leaving his country wide open for invasion.
6. The player bordering has aggressively concurred a neighboring AI and sent troops across the sea to attack, not even investigating "fakexxxxxxx"'s unguarded territories.

This is all circumstantial evidence and could be explained by being a total lev 1 nube. Is it enough to even complain about? I just want to unshared map to be safe.