Does Tanuki Shapeshift break getting through bars?

I'm running beginner box and one of my players is a Tanuki. We got to the first kobold area with the door that needs a thievery check or athletics to open. No one had thieves tools and could not roll high enough to force it open so the Tanuki player said they would like to use teakettle form to turn into a marble, or something like that so another player could toss them through the bars to the other side with the crates. This seemed like it could cause a lot of issues down the road if I allowed it now (we're running AV after) where it could break future skill check requirements/puzzles.

My question is did I make the right call or should I have rewarded the player for making use of their ancestry feat?

Appreciate your thoughts.