I'm sure there is a reasonable explanation,every one knows that by usingtodays modern laws of physics it is an impossibility for a mechanical head not to function properly every time.[8D]

Could itof been the make, yearor model of bow. Maybe the bow is tunned to poorly for proper function of head.
What kind of tree were you in? Was it a mechanical broad head friendly species?
Was your safety belt used properly for the type of tree stand you were in?
Was the outdoor temperature within the operating range of this broad head?
Carefully place the broad head on your table ,then turn your head and look at every other aspect of your hunting package for possible problems, it might take some time but eventually you will locate the source of your problem.

There are some guys out there that can point you in the right direction with a broad that will function every time.