If a watchdog EVER bites, you have a problem.

Then the natural question would be "why use a watchdog?"

The answer is "to make sure a problem is not a disaster".

As an exmple a pacemaker: if the watcdog bites, the unit may skip two beats, if that happens often (e.g. every second) the patient dies. However, if a new type of airport security machine happen to affect your pacemaker, the watchdog will keep you alive (you walked away from the security gizmo) HOWEVER, if the security people make you stay at the machine, you will have a heart attck. So, of course, the very moment that a watchdog hit is reported (the report will not say "watchdog hit") you must immediately investigate why it happened and remove the cause.

Erik