I hate to keep reporting these deaths, but it is my job.
This death was in the bike ride portion, a less common segment to die in. By the time of the bike ride, it is no longer the panic of the swim with many competitors trashing around you. Given that it occured this late in the event, the death would be more likely a result of the long duration and the accumulation of stress hormones and simple exhaustion of muscles of the heart operating in ischemia.