In Rex: Final Days of an Empire, it is possible for the following sequence of events to occur:
- Sol Offensive is revealed as the Influence card and affects a zone occupied by the Sol player's troops (allowing him to move said to anywhere on the board).
- The Sol player places some number of troops in a space occupied by another player (e.g. Letnev, but it is irrelevant).
- The Sol Offensive is completed otherwise, and a second Influence card is revealed as a Temporary Cease Fire.
- The Sol player and the Letnev player (who would otherwise have battled) now form an alliance.
Now, the placement of the Sol player's troops is illegal (the rules state you cannot place troops in a space occupied by an ally's troops). According to the rules (or an official ruling or FAQ), what should be done?