According to the description for Doc Ock’s green skill at five covers, it deals X damage, then stuns a random enemy for 3 turns, reduces enemy AP, and destroys a countdown.
However, the effects are not actually applied in this order. The stun will sometimes be applied to a character who is downed by the AoE damage, wasting its effect.
The skill should be re-coded to use the order of operations in its description.
Or re-word the order of description. 
That would be the easy fix, true… 
Making it work as worded would be preferable, though.
While he’s doing all that, he should also brush Beast, water Groot, and give Wolverine a manicure…
And stop sucking Fury’s you know what.
… cigar?
Back to the original point, it’s also important to do this in the right order for countdown destruction. This is harder to verify as a player, but if damage is being applied last, it could destroy a countdown from a character who’s going to be downed (clearing all of their countdowns) instead of one from a remaining character.
His abilities are not a list of sequential events. This is a description of abilities for 5 green covers. This means that all the abilities happen at once.
It is explicitly written as having a sequence: damage first, then the other effects. To not resolve the damage before the other effects weakens an already somewhat unpopular character.
There’s no way to justify its current behaviour. The game should not, under any circumstances, attempt to apply a stun to a character that is downed. The fact that Armed and Dangerous can pick a downed character as its target for the stun effect is a bug.
Now, if the effect happened in a different order - stun, then damage - then this would be questionable behaviour but otherwise fine; it’s simply bad luck that the character you stunned then got downed by the damage portion of the ability.