Fratemate,
Yes this is correct. Although now that I read what I wrote, it is a little innacurate because I said:
TCAS can only reverse once per encounter, and that already happened right at the start.
This is perhaps a little misleading because you aren't like to get a reversal at the very beginning of an RA, TCAS needs several seconds to assess the danger (I forget how many exactly, I no longer have a primary role as a TCAS insructor and I fly a desk these days). Then you need to fly the reversal. So we're are probably at
least 15 seconds into the encounter. So at low altitudes there probably wouldn't time for a second reversal anyway.
Of course this doesnt change the basic thrust of the arguement - we want the intruder to stop manouevering asap, and the best way to do that is to get ATC to stop controlling it with the call.
pb