I can answer with a personnal experience about a Ti frame
A friend who was riding mountain trails with me, had bought a Titanium MTB frame and transfered all the components from his old bike on it. He was doing his first ride. After the mountain ride, we were coming back riding the streets when a car did hit both of us. I was lucky and jumped on the sidewalk, ending up with minor injuries an a crooked wheel. My friend was on the street with bad pain on knee and leg, and his new bike was bent like a banana. 20 minutes later the car driver was filling the papers with him, to claim his 1500$ frame to the insurance company. We heard a sudden crash noise behind us and jumped aside, thinking that another car was going to hit us. It was his frame, that had suddenly sprung to its original shape. He is still riding it today, 9 years later.