The rules state that, "Both the active player and reacting player can take an opportunity action with any unused unit." Does this include an activated unit?
Say an active player activates a unit and spends 6 APs moving him. Then the reacting player takes an opportunity action and fires and misses. Can the active player then take an opportunity action with the activated unit to fire back? This would save him from having to expend CAPs to fire if firing cost more than 1.
I spent 100 Geek Gold and all I got was this lousy overtext message!
No, once the unit is activated it's no longer considered unused. Hence the examples of adding additional CAP's to complete that last firing action you describe when you don't have enough AP's remaining.