Capt Pit Bull suggests that following the RA is appropriate some X percentage of the time, and maybe inappropriate some other percentage (100-X). (He chose X = 0.1, but I presume he was illustrating his point, rather than suggesting a real value for X.) One of the main issues with TCAS, for me, is that no one knows what the value of X is.
What if it turns out to be 50?
Peter,
You're quite correct, I was not attempting to be scientifically accurate but rather speaking conceptually, (I'm not even remotely qualified to try and put a precise numerical value on it).
regards,
pb