[anematode]

Well, yes and no. For example, coverage-guided fuzzers won't reliably find the taken branch in

  if (hash(x) == 0x12345678) {

  }

Of course this is contrived, but you can imagine something similar where it requires a delicate setup for that branch to be taken at all, that a human (or these days, an LLM) can find straightforwardly.