It's not brilliant. They easily got caught, and it's incredibly stupid given they were previously caught and punished by the league for filming the exact same thing. This isn't a genius cover to find a way to do it another way. The promotional or documentary filming of an opposing team's sideline and signals is still filming. The predicate reason for filming the same does not change the content of the film, which is clearly against the rules to do. The Patriots organization sanctioned and encouraged a documentary series that illegally films an opponent's signals. The Patriots organization has access to this film. Whether you believe they looked at the film or not, it is incredibly stupid, and especially egregious considering their history of committing the same violation.