Normally turning left is at fault but there are circumstances where its not true. Mrs Lam is sure not at fault.
She was turning left while the coast is clear. Which is a safe and normal thing to do in this situation. Wouldn't you turn when its clear?
But during the turning process, a car which was going straight, didn't see Mrs. Lam's vechicle and try to pass the intersection while its yellow light (meaning please proceed with caution) Which the "defendant" should have done. If the "defendant" just proceed blindly then he/she is at fault.
In general, Mrs. Lam is not at fault and has the right to claim ICBC for the damages.