It wouldn't take long to tell if it's a Cornish cross. They grow very quickly, especially the breasts. Give it a few weeks and post new pictures if you are still questioning this chick.
It could still be a California White without the spots. It also could be something else. TSC is well known for mixing up chicks, as are hatcheries. This chick could easily have been a leftover from a previous batch of chicks that an employee put with in the CW bin simply because they looked...