There seem to be two different senses of what an "engineer" is. In one sense, it is "someone who has trained as an engineer", and in the other it is "someone who does engineering". Elon Musk fits the first, because he has trained as an engineer, but does not fit the second, because he is currently employed as CEO. I fit the second, because I am currently employed as an engineer, but do not fit the first, because I was trained as a physicist.
If you are arguing semantics, please take care to understand that not everybody has the same definitions of words as you do. Without the context of how you interpret words, your posts will fail to convey reasonable information.
"But actually almost all my time, like 80% of it, is spent on engineering and design. Engineering and design, so it's developing next-generation product. That's 80% of it."
"At Tesla, it's working on the Model3 and, yeah, so I'm in the design studio, take up a half a day a week, dealing with aesthetics and look-and-feel things. And then most of the rest of the week is just going through engineering of the car itself as well as engineering of the factory."