I'm not a fan of Mika, but in this situation I think the shot was obvious enough that he was playing the 9 ball. Some combos/banks/kicks/caroms are not obvious, but some are, and that one certainly was.
This same thing happened to me in a weekly 8-ball tournament last week. On a kick shot, I said "right in", maybe a bit too quietly, and when I made it my opponent claimed I hadn't called it. I let him have it, partially because I didn't want to argue, and partially because I had no shot on my next ball (the 8 ball). In the end my opponent misplayed a shot terribly and gave me ball in hand, I think he felt a bit guilty.
But anyway, my point is there are some cases of combos/banks/kicks/caroms that might even be more obvious than straight in shots.