Classic tradeoff (Score 5, Insightful)

It's amazing how fast a filesystem can be if it makes no guarantees that your data will actually be on disk when the application writes it.

Anyone who assumes modern filesystems are synchronous by default is deluded. If you need to guarantee your data is actually on disk, open the file with O_SYNC semantics. Otherwise, you take your chances.

Moreover, there's no assertion that the filesystem was corrupt as a result of the crash. That would be a far more serious concern.