For a person to be found guilty of gross negligence manslaughter the prosecution has to prove that he - or she - owed a duty 
of care to the victim and negligently breached it.

It also must be proved that it could be foreseen the breach would give rise to an obvious risk of death, that it caused the death 
and - most challenging of all - that the circumstances of the breach were so reprehensible as to justify the conclusion that it 
amounted to gross negligence and required criminal sanction.

That sets the bar very high for the prosecution.

The defendant's conduct must fall so far below the standard to be expected of a reasonably competent and careful person in 
the defendant's position, that it was something truly, exceptionally bad.