5-STABLE softupdates issue?

Greetings,

out of fun and to investigate claims about alleged bgfsck resource
hogging (which I could not reproduce) posted to
news:de.comp.os.unix.bsd, I pressed the reset button on a live FreeBSD
5-STABLE system.

Upon reboot, fsck -p complained about an unexpected softupdates
inconsistency on the / file system and put me into single user mode, the
manual fsck / then asked me to agree to increasing a link count from 21
to 22 (and later to fix the summary, which I consider a non-issue). A
subsequent fsck -p / ended with no abnormality detected.

Unfortunately, I haven't copied the details, assuming they would be
copied into the log, but they haven't.

Is this a situation the current 5-STABLE softupdates code (on a UFS1 FS
that I kept from FreeBSD 4) is allowed to cause?

Is that a bug in the file system, say, write ordering goofed up?

Or is that a bug in the firmware of my disk drive (Western Digital
Caviar AC420400D, a rebranded IBM DJNA drive)? I gather that ATA drives
are supposed to flush their caches on software (command) and hardware
resets (reset line active).

I did not power cycle.

-- 
Matthias Andree