It sounds like your son is, and that is all that matters.
I would be taking hold of this situation, not because of his feelings and what he can distinquinsh, but because an almost 4 year old is not a little adult who gets to decide what his Mommy tells him and how. It really does not matter that he does not like you to interfere, if you see something to teach him, tell him, have a safety issue, or just want to put a limit on him, that is how it is. Almost 4 year olds may throw fits when they do not get their way, and that is expected, you deal with the fit, apply dicipline consistently, and let them learn that some behaviors are just not OK, and for my family, a child telling an adult what not to do is not acceptable. Just my two cents, but then, I do not buy into the idea that I am here to make my children happy all the time either, I think kids need to learn what they need to learn, and sometimes, that means that they will not be happy. Our guidence for our kids is essential, there is not choice about applying it when they don't like it.
M.