Expect the orca people will be along to explain about how he was a billionaire and deserved it any moment now.

Seriously, I think the main thing determining whether dolphins (including orcas) attack humans is whether they think they can get away with it. Nasty little twats, they are.
asahi.com/ajw/articles/1495829…

Swimmer left with broken ribs after dolphin attack in Fukui | The Asahi Shimbun: Breaking News, Japan News and Analysis

A swimmer in his 60s was left with broken ribs July 16 after a dolphin rammed him in shallow waters at a beach in Fukui Prefecture.

^{The Asahi Shimbun}