Most people wouldn't think twice about someone getting up and walking out of the movie, I kinda doubt this guy had an accomplice, he walks out and uses anything to keep the door open, comes back in.
As far as the court appearance, I'd say lack of sleep, getting used to jail schedule, who knows what his sleeping habits were like in the last few weeks, I'd say erratic at the minimum, if not fully dysfunctional. I bet he's been slowly getting worse and worse for the last sixth months, mental stability wise, maybe this was set in motion by a rejection, or something else unknown, but he looks pretty deteriorated at this point.
It is possible he has been put on medication, esp. if he was abusing scripts before this, as soon as you are booked, they ask you if you are currently using drugs/alcohol, and at what volume, they don't people withdrawing and dying in their custody. Plus, if reports are true he was spitting at police and acting irrational, he may have been given medicine, he may have been on some heavy shyt, prescribed, anyway. A lot of questions up in the air for now. But, I don't think he's faking, in some sort of bid to be declared insane.