Alice didn't know how he knew about that incident. Well of course he knew, he could read minds.
"Tyler is harmless. The car was out of control. It wasn't coming after either of us. Would you rather I let it hit us and expose my immortality and spill Tyler's blood? Plus Bella has TONES of protection. She will be fine. She would be better if you changed her." Alice said with a hint of annoyance. She didn't know why her brother was waiting. She had already seen Bella as a vampire.