You broke the rules "May still produce infantry units for use in Combat Chinooks and for capturing buildings. However, infantry are not allowed to garrison buildings or engage in combat while not in an aircraft". Your missile defenders did engage in combat outside a chinook at 7:33 against the sneak attack + enemy units and also at 10:55 against the bunkered helix. The rules below that one only mentions exceptions to that rule when controlling "Rangers" should they engage in combat but you didn't mention any exceptions to Missile defenders at all in the rules.
You broke the rules "May still produce infantry units for use in Combat Chinooks and for capturing buildings. However, infantry are not allowed to garrison buildings or engage in combat while not in an aircraft". Your missile defenders did engage in combat outside a chinook at 7:33 against the sneak attack + enemy units and also at 10:55 against the bunkered helix. The rules below that one only mentions exceptions to that rule when controlling "Rangers" should they engage in combat but you didn't mention any exceptions to Missile defenders at all in the rules.
Oh dear, you are right, that is embarrassing. The heat of battle can be too frantic to notice.