Hello Coprtop and thanks for your post.
In California, there is not a redemption period after sale. Once completed, the sale to a bonafide third party is final. The only recourse the previous owner has in the event of an error is usually a lawsuit against the bank. However, for the best and most accurate legal opinion, please discuss this matter with a qualified real estate attorney in your area.
Grace Morioka, SRES
Area Pro Realty
San Jose, CA