No I think it's Big Brother who looks stupid. Surely Brian has forfeited his right to a party. Prior to his being told, he was critical of those who suggested Pauline maybe fake. Then he used this knowledge to put her on the end.
Having said that it was inevitable tthat she would end up there, considering what some of the housemates have said since her arrival. She has only been there a couple of days and would be certain to attract the most suspicion. Do you think BB hadn't achieved the expected result and therefore wanted her out?