If your teacher leaves the path which you believe and practice, keep going! This is especially the time to move forward in love, honesty, and Divine Love and Light. Take the teachings that lift of your heart and teach them. There is no reason to think they are invalid. The teachings and information that you felt, knew, and honored at the time your teacher passed them to you--are still valid as they came from Divine Love and Light. You don't need to hide behind the name of others to prove you have gifts or to teach or spread love and light. If people ask where you were certified, what your credentials are--that's easy! You can say, "I am a Child of Divine Love and Light. the Divine is my teacher." Certainly you can let them know you have taken classes and courses to hone your abilities and skills, but they are your abilities and skills.
Stay true to yourself, your path, and your heart. Take the information that you gather and use it for the highest good of all concerned, leave the rest.
Be your own guru. Placing another on a pedestal will ultimately disappoint you and dis-empower you. EMPOWER YOURSELF! Stand in your truth, honor your Divine guidance, and your Divine connection.
There is no reason to be upset by a teacher changing their stripes. They are human, and humans fear sometimes, get off track sometimes--yep even the best ones! But you, my dear child--you can stand in Love and uphold the Light. You can move forward in confidence that you learned from this teacher so you could pass on this information. For the information is bigger than the teacher--always!
Take what resonates for you and pass it on. Live it. Teach it. Be it. Let go of the rest. Be amazing! Be you!