How about this as a movie plot....?
It turns out the the whistleblower fella, aggrieved due to being recently sacked by Saints, set about framing our spy chap by telling him that Middlesbrough didn't mind analyst's from other clubs watching their training sessions, even within the 72 hour embargo window.... Being familiar with the Middlesbrough training complex, he told our guy exactly when and where to stand, where best to get changed, where to get a coffee... And the whistleblower then positioned himself ready to take the perfect photo of the 'spy' himself... Revenge mission complete... maybe call the movie "You've Been Framed"....?