I would find it strange if the little prick had all-of-a-sudden undergone a massive personality change and actually became talkative, engaged, and friendly.
And he already knew more than anyone else anyway.
Right, I know you're being "provocative" <g> but back to my point: he apparently showed no interest in the events? He didn't stay around the TSBD and watch what was happening? Listen to people? He just leaves within, reportedly, about three minutes?
Mrs. Robert Reid, an office worker in the building, said she went back into the building after hearing the shots. She testified that she saw Oswald walking in the second floor and said to him (para), "The president was shot; but maybe they missed.."
He, according to her, mumbled something she couldn't understand and kept walking.
Is that what you'd do? Not me. I'd ask if she knew anything more about it.
Oswald was a deeply politically engaged person. Piper and Dougherty were, based on what we know, not those types. They were, from what they said about themselves, simple workers trying to scratch out a living. Completely different types of people than Oswald.
Anyone who finds their behavior curious but not Oswald's is believing in some very odd things.