Comment 3 for bug 382440

> The fuser-generated output seems to be missing information;

It's not. The apport hook is buggy - fuser always exits non-zero when no matching processes are found. And none of these devices were open at the time.

Killing pulseaudio and restarting it seems to have caused it to right itself, for no clear reason. I'll retest in a bit to see whether the problem is reproducible with a logout/login.