Under California family law, any community property not divided during the dissolution is considered "omitted property." Either spouse can return to court at any time for a supplemental order from the court finally dividing the property.
Ordinarily, spouses have a fiduciary duty to each other and neither can gain an unfair advantage over the other prior to the final judgment of dissolution -- or the court will rescind any transaction where an unfair advantage was obtained.
After dissolution, however, the fiduciary duty is terminated with the judgment of dissolution. So, if the quitclaim
was signed after the dissolution, the court would almost certainly enforce it against your ex-spouse, and he would be unable to claim any value from the property.
That said, there is no case law or statute which absolutely disposes of this particular question. It's actually quite a novel question of family law. I'm pretty certain that my answer is correct, but I cannot say it for an absolute certainty, because no appellate court has ruled on a similar set of facts (to my knowledge).
The presumption, at this point, however, is that your title is valid, and your ex would have to overcome that presumption by clear and convincing (overwhelming) evidence that he was deceived into transferring title to you. Evidence Code 662.
Hope this helps.