Go here to register (top right): http://tfbt.nuvturais.de
It didn't like my squad tag, so I had to register without it. It took 4 days for the account to be activated. I'm assuming that means they are manually cleared, so be patient and watch for the email (mine was in the Junk folder).
You can navigate there after logging in, but the page for this bug is http://tfbt.nuvturais.de/issues/574
Just click the UP arrow next to Votes.
Looking through the entire bug list there are certainly a few I'd consider priorities, but for our purposes at GS, the stats aren't just there to be trophies. Recording them accurately is how the campaign drives itself. So this would be a really big one to get fixed. I've seen it many times on what were legit kills on ATAG. If our votes give it some added attention, please help out. Thanks for bringing this procedure to my (our) attention Matte.
From what I can tell, the game isn't sending the ditch message to the server. The log just said that Stachl was recovered by friendly troops and that the plane was lost (when he left it). Since there was no ditch event, it doesn't credit those who did the damage, and there's no kill for any parser to record. GS does have a damaged systems tally, and somehow it can vastly outpace the actual game messages that notify you of specific damaged systems. It doesn't specify in the stats what systems were damaged, just how many. But it only records such information on planes that are returned to base in damaged condition. When they are lost, as in this case, it doesn't indicate anything about the damage stats.