Well, if there's a source of radio waves then radio detectors will be able to detect them. Even if your friend's radio is disabled by circumstance, he can still hear other radios detecting the waves, so he knows they're there. And he can tell he's oscillating using accelerometers, so even assuming that the oscillation disables the radio he can correct for it and make his radio inertial.
You detect radio waves using the motion of electrons in a wire under the changing electromagnetic field of the wave. If you oscillate the wire I think you will cause the electrons to oscillate along with it, and they will be further accelerated by the electromagnetic field of the wave. So I think you'll still get a response from the receiver.
Remember that your friend can detect whether he is moving inertially or not in an absolute sense. So he can tell whether the charged particle holding position infront of his nose is moving inertially or not. It is, therefore, not at all obvious that he shouldn't expect EM radiation.
