Yes, it is wrong. The curvature of the sail lowers the leading angle of attack which promotes attachment, i.e. reduces the risk of stalling at high angles of attack, but it is not responsible for lift in the sense you mean.

It could be argued that preventing a stall makes it responsible for lift in an AoA regime where the wing would otherwise be stalled -- hence "responsible for lift" -- but that would be far fetched.

More likely the author wanted to give an intuition for the cuvature of the airflow. This is produced not by the shape of the airfoil but the induced circulation around the airfoil, which makes air travel faster on the side of the far surface of an airfoil, creating the pressure differential.