I also wondered at times if it was meant to be a comedy.
I did like the line when Karin said to her Dad, as she thought, "I saw Erik." He replied, still in the persona of Adam, "That's me you saw." Perfectly true, as it happened!
As for the Policeman taking her home - perhaps in a very small community, they do things like that?
But then in a small community, how do you avoid a brother for 15 years? Having said that, coming from small towns myself, I do know families where the members are estranged and do manage to avoid each other.