On the basis that 'It's the volts that jolts but it's the mills that kills!", if the current is high enough, then the RCD is doing its job. OTOH, if the current
isn't high enough, then the current through you - although unpleasant - will not be of a sufficient magnitude to kill you - since the ultimate function of an RCD is to prevent that result.
Or have I over-looked something in all that?
Perhaps I'll do an experimental lash-up to investigate . . . .
Al.