Black Swans in Perth, herdsman Lake and elsewhere, in the 1980s during breeding season (and likely still today) fully charged people and had the mass to knock over more than one kid or small teenager .. and scare the bejeebus out of many adults.

As I said, and supported by your link, I can't see a swan directly breaking a human bone - but they sure as hell can knock one arse over by charging and causing a step back fall over. That'll do some damge in some cases, easy.