For much of its early distance, the 2003 British Grand Prix was shaping up as a fairly conventional affair, with the front-runners settling into the rhythms of a long, dry afternoon at Silverstone. That changed abruptly on lap eleven, when a man later identified as Cornelius 'Neil' Horan — a defrocked Irish priest with a history of disruptive protests at major sporting events — climbed over the trackside barriers and ran directly onto the Hangar Straight, one of the fastest sections of the circuit, waving a religious placard while cars approached him at racing speed.
The scene that followed was genuinely alarming rather than merely eccentric. Drivers, arriving at well over 150mph with essentially no warning, had to take evasive action to avoid a collision with a man standing in the middle of an active racing line — several cars swerved sharply, and the incident could easily have ended in serious injury or worse, either to Horan or to a driver forced into an emergency manoeuvre at speed. Marshals eventually wrestled Horan from the track, and race control deployed the safety car for an extended period while the situation was brought under control and the barriers were checked.
The lengthy safety car intervention scrambled the strategic calculations every team had made heading into the race, bunching the field back together and effectively resetting much of the tactical advantage that had been built up in the opening laps. When racing resumed, the shape of the contest had changed considerably from what it had been before Horan's intervention, and the closing laps played out as a genuinely different race to the one that had started an hour earlier.