[bobdsmith]

That is, would they be able to determine that it wasn't, or in all likelihood wasn't, the result of a non-"supernatural" cause?

Not unless they fully understood every aspect of how it formed and worked. Otherwise I don't see how they could be certain that a natural explaination won't turn up tommorow.

For example long ago the prospect of a rainbow or thunder storm having a natural explaination would have been ridiculous. There was just no fathomable natural explaination for those things. Yet that was clearly not a good reason to assume a lack of natural cause.

[inquest]

Just for the record (just because others have tried to make a semantic issue out of this), do you consider there to be any meaningful distinction between natural and artificial, or only between natural and supernatural? There are those I've come across who insist that the only distinction worth considering here is natural vs supernatural, in which case a car would be considered "natural". I'm just trying to lock down the terminology, if you don't mind.