Pavonis Interactive Forums

I'm playing Long War for quite some time now and I always heard the rumor of bonus XP given when a low ranking soldier kills the outsider, or sees him, I don't know which version is true. I found a reddit thread from a year ago stating that it doesn't work, but it also didn't become clear how it's actually supposed to work. Can someone here please explain if there is such a mechanic and if yes, how it actually works?