Earlier in his career, Hamilton was criticised for being hot-headed at times, as demonstrated when he was disqualified in Imola in the GP2 Series for overtaking the safety car, something he went on to repeat four years later in Formula One at the 2010 European Grand Prix in Valencia. Following his move to Mercedes, Hamilton was credited with demonstrating greater maturity, while maintaining his ruthlessness and aggression. The official Formula One website describes him as "invariably a fierce but fair fighter".