May be difficult to reproduce in a way that would help the bug fixers on the right track. If it is totally random, as azaroth said, the exact cause may be very hard to pin down.

It’s not totally random, of course. Something causes it. But as long as we don’t see a consistent pattern, it seems completely random. So the best we can do is keep reporting these events to Funcom via the proper channels and hope that once the bug hunters get enough reports, a pattern emerges that helps them figure out the cause.