Missed it by that much ...
All three squads would be subject to a single defensive fire shot in that hex. If you look at Rule 16.1, it says that
the defending player may return any enemy units which just moved through a hex in the LOS of one of his units to any target hex which they traversed during the just completed Movement Phase. Stacking limits are temporarily ignored.
I would be happy to help you out with rules questions, at least through the Squad Leader rule-set. I am just starting to get into Cross of Iron myself. If you want a more comprehensive Squad Leader resource , check out www.advancephase.com, which has its own mailing list for questions like this. You will also find lots of additional scenarios, tactics articles, tournament info, etc.
There is also a pretty dedicated group of Squad Leaders who participate in a ladder, using VASSAL -- we have a dedicated module that is a stand-alone (VSQL). It supports both vFTF and PBEM, and it is pretty easy to install. Again, there are plenty of people who would be willing to help you out with it.
Come check it out!
Aim well, roll low, and have fun!!