Many events that create forces do not bother to check if the target region is controlled. This leads to units being created in hostile territory with no chance to escape being slaughtered. Rather than receiving a free unit the end result is that the opponent gets free VP and possibly NM from an easy kill.
Possibly the worst of these events is in 'evt_nam_USA_CapitalDefensesBeefedUp1861'
If Alexandria is lost or abandoned to the CSA, five Union volunteer brigades will still be created in the region in November of '61. These brigades will be locked for 60 turns, they have no option to retreat or be disbanded, they are simply created to face certain death.
If there is any interest in fixing these events, I'd be willing to help.