This question has come up often in the past. In my opinion, the answer lies in whether or not the energy stored in the rod is derived from the mousetrap, or is in addition to it. With the mousetrap bail in the "locked and loaded" position, is the rod bent from its relaxed state? If so, it contains energy in addition to that stored in the mousetrap and therefore violates the rules. If the rod is bent only after the mousetrap is released. the energy stored in the rod is derived from the mousetrap and does not violate the rules.
This may be subject to different interpretation by diffefent judges. Only the judge at the tournament where you will compete can answer the question with any degree of certainty.
Information expressed here is solely the opinion of the author. Any similarity to that of the management or any official instrument is purely coincidental! Doing Science Olympiad since 1987!