In the Harry Potter universe, it's possible to use magic unintentionally, the most famous example in the books is probably Harry blowing up his aunt.
Is there any reason to assume that wizards could (by accident or just because they're really mad) kill someone by this mechanism? What stopped Harry from actually blowing up his aunt? (Or just make an artery in her brain burst/ stop her heart etc)
I can't really believe that there is a system by the Ministry of Magic to prevent this kind of magic, because if there is, why doesn't it go as far as stopping Harry using magic in this way entirely?
I'm interested in a canonical answer (eg. information provided by JKR) since anything else is quite trivial.
EDIT I'm talking about a direct kill, not a death as a side-effect of an unintentional spell (eg. someone being killed by the snake Harry released)
EDIT 2 To clarify: By direcet kill I'm talking about a death resulting from a release of magical power caused by a thought like 'I want you to shut up'. Imagine that 'the magic' just takes it too far. For example: Harry inflated his aunt because he wanted her to stop talking, would it be possible that his aunt is actually killed by bursting, because that would definitely shut her up. In this regard, death is a side-effect, to the intention, but it is fulfilling the casters task whereas if the snake that Harry released were to kill someone I would not count it as a direct kill, because Harry did not release her with the intention to, for example, stop Dudley from talking trash about him.