If daemon's -P option is used without the -p option, the pidfile is not removed when the process terminates.  To demonstrate:
/usr/sbin/daemon -P pid.daemon sleep 5
After sleep terminates, pid.daemon is left around, pointing to a nonexistent process.  It also seems that there is no separate daemon process, as the pid.daemon file points to the sleep process.

The danger of leaving the pidfile around is of course when pids cycle around an unintended process might be terminated.

This might be treated as a documentation bug, as using -P without -p or -r is at least unusual.