We all seem to be saying the same things in different fashions, after all, we are ALL interested in safety, we do not choose to cause 2 aircraft to occupy the same position in space and time simultaneously.
FROM THE ATC SIDE.
Unless the pilot specifically (and clearly) tells the ATC that he is responding to an RA, there is no way that the ATC can KNOW this, and as such he/she will continue to try and keep two aircraft apart as long as they are on radar and/or frequency. This is a fact, and it is a simple truth. ATC's are trained to keep aircraft apart, and when things go wrong, the adrenaline flows, the heart pounds, and the mouth rattles. It is even possible that the ATC may experience temporal distortion in the death throws of a near-miss or mid-air.
The equipment solution could be by one of various means:
1. RA in cockpit forces special code (7400) to be transmitted by tx-ponder, causing RA to flash on the callsign block of the label. (This would probably be the cheapest solution). The problem is that the rate of update for different radar systems can vary between once every 5 seconds to once every 12 seconds.
2. The (ground based) radar software could be programmed with the same parameters as TCAS II (v7), and then, based on aircraft positions, indicate (by whatever means) that it (the software) "expects" that two specific aircraft would be receiving RA's at that point. I know that this is not a fool-proof system, but it may be a means to at least cause the ATC to "consider" that aircraft may be manoeuvring under RA instructions. (This method would require development of ATC software and updating of existing systems).
3. Mode-S or ADS-B systems that communicate specific data to and from ATC software and airborne software, to immediately update (in near real time) each other of their actions. (This would probably be best, as there are other major benefits). This concept is still only partially operational, but still has some major development to undergo, is costly, and requires vast & major upgrades when it goes fully operational.
As a side-thought, the ATC is responsible for keeping the aircraft apart (by means of Standard Separation). Once the ATC, for whatever reason, has allowed that separation to become eroded, the pilot has TCAS to avoid "a hit".
Methinks that there is sufficient technology available to avoid the mid air collisions, all that remains to "perfect" it, is the GLOBAL acceptance of the requirement to standardise procedures with regard to TCAS as well as the mandatory fitting of TCAS II (and latest version software) to all commercial aircraft. Yes, this (retro-fitting) is expensive, but what price do we place on a single life? 10 lives? 100 lives? 1000 lives?
Best Regards
SID