We do not have to argue about this if you think it has to be this way.
Just for the sake of correctness: A nullpointer exception is a bad analogy. Not only does the child function exist in this case (so not a broken pointer), the compiler also tells you that it’s a nullpointer exception (the exact problem). In this case the error message states that the child function does not match it’s parent. That is not correct, it does. The child function, however, is broken (visual studio, to keep your example, would point me to where my class/function has a problem).
This is not a runtime error. This happens during compile time. Debugging information during compile time are (normally) rather accurate (including most cases I came across in the editor).