If there is any choice, overpower the problem rather than trying to finesse it. In poker, one Smith and Wesson beats four aces. In engineering, one positive fix beats four probables. This faithfully follows the theory that if a little bit goes a long way, try a lot. Confronted with a failed part, any metallurgist worth his salt can always find something wrong.
Every engineer knows that even a very good design can suffer a random failure.
He sometimes forgets that even a bad design can sometimes enjoy a random success, but the fundamental weakness remains. If you have a theory, have the courage to put to an unbiased test. The theory is not proven until you can turn the phenomenon on and off at will. It may never happen again. Once the drawings are changed, once the parts are ordered, once the test plan is written, once the failed parts are sent to metallurgy, it is tempting to sit back and relax knowing that someone else momentarily has the ball.