The way lighting works in-game vs the editor tools is a little different I believe (these kind of comments come up fairly often as a result).
So, seeing as it's happened (at least) twice, and you guys know exactly why it's happening... why is it still a problem? It's as easy as a checklist.
I might be wrong about this so don't hold me to it! None of the artists were available to comment at the time so I went with what I thought might be the case (hence "I believe")...
I will ask one of them to confirm :D