The 1984 BRDC International Trophy (formally the XXXVI Marlboro / Daily Express International Trophy) was a Formula Two motor race held at Silverstone on 1 April 1984. It was the 36th running of the International Trophy, and the seventh and last under Formula Two regulations. It was also the opening race of the 1984 European Formula Two Championship.
At least one more race followed the 1984 BRDC International Trophy race in the 1984 European Formula Two Championship.
The passage states that the race opened the Championship, so at least one race must have followed it. The model was fooled because this is a logical deduction that isn't explicitly worded in the passage.