I downed a lander without killing the two heavy fighter escorts and then had my three fighters retreat. It left a crash-site that I cleared. After finishing the ground combat mission, I noticed that the crash-site was still there. When I sent the chinook back to check it out, it was downed by "enemy fire" which I assumed came from the two remaining heavy fighters (it didn't show a combat, just the message you'd get if a fighter hits your chinook). When I sent my fighters back to the fake crash-site, they just turned around and left after reaching the site. Eventually it just went away like any other crash-site does if ignored.
I don't know if it is working as intended or a bug, but I thought I'd post it. If it is working as intended, I wonder why the heavy fighters didn't just down my chinook the first time around and if it is a bug it isn't really game breaking since we can just ignore the second, fake crash-site. Just wondering if anyone else has run into this one.