I just tried it here and it appears that the -p switch just prevents the timer from executing until it's resumed. So if you pause and resume within the 10 seconds, the timer will still trigger at the normal time. If the timer is late (as it does every time a timer is late), it'll trigger as soon as possible. It's not necessairily a bug, just the help fails to explain the behaviour.
It also appears to restart the clock each time it's triggered, unless you use the -c switch.
