The pilot to put it bluntly was an idiot... RADAR is far more accurate in azimuth than TCAS/ACAS. That is one reason why it is expressly forbidden to use turns for TCAS/ACAS RA's. Use the vertical all you want as that is VERY accurate, but azimuth is NOT. We see pilots who do try to second guess what you are doing with TCAS all the time, we have just become accustom to it, and feel, FINE, just do what you are told. (sequencing) It is far more difficult to do the job when a pilot is trying to "help" you with spacing and things of that nature.
regards
Scott