I agree, I see nothing unethical about tailoring your various job-related communications to the type of person you're speaking with. Especially at large firms, HR employees are often quite literally just looking to check off boxes. Obviously you should not outright lie, but we engineering types have a tendency to take these sort of questions too literally.

I use C# at work. I've programmed in Java here and there and have done some small projects in it, but we don't use it at my office. If I apply for a Java job, and the HR rep asks me during the 1st round phone screen if I have Java experience, I'm going to say yes. When I speak with a more technically minded person, I can go into the full story, because they have the background necessary to put it in context.