I find it difficult to believe that there should be no active and real-time monitoring by the local military of their radar returns,
One reason could be they are looking for traffic coming into their area, not transiting / exiting.
Secondly, if there is any correlation between the civil and SSR side, the primary return could have been verified as a known / identified / flight planned "target", and thus disregarded / categorised as low risk.
Finally, retrieval from tapes is required in the civil world for various reasons. In the military world I suspect less so, since the basic requirement is real time. Think through what the military system and radar is implemented for - a backup civil / SAR is not high on the priorities.
NoD