SK? You mean the brother?
I think the security guard was recounting the story the one brother told him. We are left to believe the story or not. I happen to believe it at this point.
SK, yes the brother.
I believe the SG, but not what DK told him. He may be telling the truth about the vdS "family" involvement with making up the story, but DK may be not be truthful about his whereabouts that night in order to save his sorry @ss.