He's good at what he does generally, but you get the sense that he doesn't trust his technical ability in certain situations. This is most obvious on the numerous occasions that he tries to bring the ball out to start attacks, but then opts for the safest pass from promising positions. Prior to the own goal, there was an instance where Smalling was on the ball, and the best option available to him was a long pass to a stationary Valencia out on the wing, but he just seemed reluctant to attempt it. He did play the pass in the end, but it was overhit and went out of play.
It seemed to me like the own goal was an extension of that same reluctance and lack of trust.