Someone to Trust

The nature of secrets kept in a POW camp is that they're rarely petty; everything attracts its own dynamic and hyperbolic gravity in the living sinkhole of a luftstalag, where anyone outside must have half a foot in in order to be considered relevant, as the boundaries of the conglomerate singularity transitively, actively, offensively erode.

In plainer language, anything you don't tell your comrades (and anyone who isn't one, save the leering enemy) more or less ceases to matter.

It isn't a secret that Kinch is Hogan's designated astronomical secret-keeper, in such eventuality that one is needed. It's just...unspoken.