@Noeuf
ancientgran do you think the only options are murder or an accident? Seriously? Accidents are unavoidable - I doubt this was.
RIDDOR definition of accident (HSE)
What is an 'accident'?
In relation to RIDDOR, an accident is a separate, identifiable, unintended incident, which causes physical injury. This specifically includes acts of non-consensual violence to people at work.
So in England it would qualify as an accident if it was unintended.
a definition from the USA
When a worker is injured on the job, it is usually from an accident. The meaning of an accident can be described in several ways; however, the most basic definition is when a voluntary action results in an injury or death.
Still sounds like an accident unless it was deliberate.