He is right - the problem with your response to this statement is that it doesn't identify the _actual_ reason behind why they need to be better, and it's a problem identified by the article in question: When a human driver swerves randomly and kills someone, we know EXACTLY who is to blame, and something can be done. If a driverless car, or even a car with "driverless technology" that also has a driver in it (like the Tesla driver mentioned in the article) hits someone and god forbid kills them, we still have no idea who is to blame for that problem, because it practically becomes a marketing argument in some cases.
Before we can be okay with driverless cars, ESPECIALLY if we don't plan on them being 100% accident free, we need to solve a lot of ethical and legal battles that don't seem to be even on the minds of the people that tout this as the future, or a necessity.