Inappropriate anger and aggression is a dementia symptom. It’s possible that he is as yet undiagnosed. His family may have been ignoring symptoms because they weren’t extreme enough yet. This event most certainly is going to trigger a new medical evaluation.
And the lawyer could hardly introduce an undiagnosed medical condition. Legal strategies can change with new information and evidence.
As for the UFO, Oulsen and his popcorn were backlit by the screen in a darkened theater so they would have appeared dark. Once the houselights go down, it’s quite difficult to see anything but the screen when you are facing it, but if you have your back to it, the screen light things up quite a bit. It won’t be long before the defense figures this explanation out.
Explanation or prefabricated rationalization.
They'll get laughed out of court.
No one else referred to the bag of popcorn as a dark colored UFO.
They have a better chance with his claim of a UFO.
Afterall it's his pathway to an insanity defense.