i ask a vallid question and the the ATCO comes back with "crossing traffic" and on my TCAS (in middle of night with hardly any talk on sector) i see one Yes ONE! plane as far as my TCAS go's
Thank you for proving my point.
TCAS will only show you traffic on a mode 3/A and C squawk. Military traffic, for example, does not always comply and therefore would not be displayed and, contrary to what some believe, they do fly at night.
Not all the traffic being worked by the controller need be on one frequency, again military traffic, possibly on UHF, and if the frequencies are not coupled then you won't know anything about it.
In this case you asked where the traffic was, but not everyone does., but what was the closing angle? If it was very small, it is sometimes difficult to judge the actual separation at the crossing point. especially true at night when, due to low traffic, sectors are combined and it is probable that the controller was working all the civil traffic over the country. His radar display would be covering a much greater area than normal.
BTW. Yes , I am aware that we are down here because you are up there; and even before 911 I came across a lot more ATCOs in cockpits than pilots in Centres.