Actually, as far as I can tell, ships that are in EMCOM will come out of EMCOM once they have been attacked as long as you have the tactic set to something other than Transit and have not burdened it with a specific target.
Try it without any triggers on a AEGIS in EMCON. Fire a missile or something at it from 15nm or so. You may have to have Debugviewer running at the same time to see what radars they have turned on.
To find out about Debugviewer, check out this thread at the CADC
http://www.orionwarrior.com/forum/showthread.php?t=74 .
I'll try it myself when I have a small bit of time...
