I think O'Nien was a little unlucky to get booked, the Plymouth lad was going on like a knob.
Luke thinks he's in a wrestling match every week, qwhere its OK to use his hands. Unfortunately, he's not very good at hiding it like others are and refs are noticing it.
This "Onien is a master of the dark arts" is utter crap, and almost has the lad believing it himself, which is why he'll be sent off soon enough for a last ditch, reckless tackle or for throwing someone to the floor in the box. Take your pick.