The point I tried to make here is that there was certainly a second aircraft involved. No second aircraft call on the frequency, perhaps it was on a different ATC-sector.
ATC did not at all react to the TCAS RA call, no confirmation, nothing. As mentioned, after the pilot who declared the TCAS RA advised about an ASR to follow, there was only a surprised ATC response, clearly showing that ATC was at that stage completely unaware about the situation and that the TCAS RA call was unnoticed.
This is extremely dangerous and in my opinion a result of the "tame" expression "TCAS RA". A more prominent call, accompanied or followed by i.e. a PAN PAN PAN would advance this situation to a higher priority with the needed adequate attention.
anotherthing, my posting crossed you one.