Rio 2016 Olympics

From the Guardian article:

Viviani, who went into the final race in first place, started strongly but was knocked off his bike by South Korea’s Park Sang-hoon, who had collided with Cavendish. The Team GB rider was not penalised over the incident, and joined Hansen in taking the fight for gold to Viviani.

https://www.theguardian.com/sport/2016/aug/15/mark-cavendish-silver-rio-olympics-cycling-omnium

I appreciate these articles have to be written very quickly (and this is a problem we know from numerous on-road collision reports), but it is surely Cavendish who collides with the Korean, not the Korean with Cavendish. Cavendish stops looking back just before he makes the move and either overestimates his speed (he's clearly too slow) or there really was malice aforethought. I don't believe for a moment that he didn't see the Korean rider.

Is there something I don't know about track rules that exonerates him?