common in kingsnakes, we have recorded it at least three times.
Also Dr. Gordon Shuette, did a paper on this subject and proved that many types of snakes had this happen.
What is unknown is, why, where, when, how, etc.
I have seen twice where hybrid breedings did not produce crosses, but instead only the females normal species morph.
I believe the folks here are right, that pic appears to be a normal albino calligaster. The next step is up to you, after it grows up some, you may want to take a tissue sample and send it to someone who can test the actual genetics. Good going and please follow up on it. FR