My first piece of advice would be to go into his office and very respectfully ask him to unpack what he meant by that statement. He may have just been trying to say that you were too junior, he doesn't believe that unit tests are worth the business advantage, or any number of things.
The reason I suggest this as a first step is because it will open up the communication between him and you over something that may give you more insight as to why he would say such a statement that is so grossly over exaggerated to the point of being a lie.
The theory would then go that if you could get your CTO to open up about this subject, then they are going to be more likely to open up to about other suggestions regarding the development process/other operational efficiencies.