I don't think those bot teams (or the abandoned ones) have 0 bonus or bad morale by default.
They must have smthing like good +, a 6% ?
But as @ EastsiderSG said, that doesn't matter.
The logic of those events is like a slot machine.
They are programmed to return 25 of 100 throwing coins.
How much and who will win them is a matter of luck mostly.