The Australian fellas shouldn't be thrown in the slammer for manslaughter or anything, though - no one would reasonably have expected any physical consequences as a result of this. It would be like saying something that made someone faint, and then they hit their head on a spike as they fall and die - that clearly wasn't the intention, and it wasn't caused by carelessness like reckless driving or firing an AK-47 into the air in a crowded area. From a rational standpoint, we should be putting more effort into people who intentionally bully someone for years and then have the bullied person off themselves.
That may not be true in Britain, eggshell plaintiff/eggshell victim rule:
In criminal law, the general maxim is that the defendant must "take their victims as they find them", a quotation from the judgment of Lord Justice Lawton in R v. Blaue (1975), in which the defendant was held responsible for killing his victim, despite his contention that her refusal of a blood transfusion constituted novus actus interveniens.
The doctrine is applied in all areas of torts - intentional torts, negligence, and strict liability cases - as well as in criminal law. There is no requirement of physical contact with the victim - if a trespasser's wrongful presence on the victim's property so terrifies the victim that he has a fatal heart attack, the trespasser will be liable for the damages stemming from his original tort. The foundation for this rule is based primarily on policy grounds. The courts do not want the defendant or accused to rely on the victim's own vulnerability to avoid liability.