I'd say this is possible and not something preventable.
On a dommy the air passes past the valve which is sealed past the seat and then up to the transfer port. But the valve stem is not sealed and it's possible for air to get past that to the dry fire wedge which is also not sealed.
However it's not something I've noticed on mine. That said mine is removed and taped over. It can also escape via the hole to the left of the pellet channel as this is also not sealed.
What I would check though is that your breech is sealing. With a pellet in the gun, close the breech and put a small piece of single layer of tissue on it and fire. It shouldn't move, but obviously check it's not the dry fire.
Or you can use talc with a small brush.
BFTA/NSRA County Coach
CSFTA Chairman/BFTA Rep