The Ninth Circuit has retroactively applied the Supreme Court's decision in Holder v. Martinez-Gutierrez, where the Court held that an applicant for cancellation of removal for lawful permanent residents cannot use a parent's years of residency in the United States to fulfill the 7-year residency requirement in the cancellation statute. The Ninth Circuit applied the Montgomery Ward retroactivity analysis, and concluded that the petitioner did not reasonably rely on its contrary decision in Cuevas-Gaspar v. Holder because multiple courts disagreed with that decision, thus putting the petitioner on notice that the decision was vulnerable.
The full text of Lemus v. Lynch can be found here:
http://cdn.ca9.uscourts.gov/datastore/opinions/2016/11/16/12-73654.pdf