Merlin Recording, south Texas: Red-Shouldered Hawk or Blue Jay imitation?

While I was recording this, about half way through, I saw a Blue Jay sitting in a nearby tree, opening it's beak with every call I heard. Merlin says Red-Shouldered, and I agree that it matches a Red-Shouldered pattern, but the pitch seems noticeably higher to me. Was it the Blue Jay the whole time, or was it a coincidence? Never did see a hawk around, but there are lots of places it could have been that I would have missed.