Congratulations on the big win. And thanks for sharing.
Play at [-4;0] as CFFF and don't place a meeple. Then hope you get the last RRCC tile and complete the city at [-4;1] for 12 points. There is no other tile that can play at [-4;1] so the CFFF tile is essential at [-4;0] to complete the city and recover the meeple. Plus Red keeps a free meeple to grab another 3 points on a later turn, and maybe eek out a win.
Originally, I thought the best play would be at [4;3], placing the tile FFCF with the last red meeple as a knight in the city, which gets you 3 points if incomplete, or 8 points if you get the last CFFF tile. But then I realized that there are plenty of chances for Green to get 3 points each with their last 2 meeples (e.g. farmer at [-1;6] or [4;-5], thief at [3;1]). Red would be without a meeple until the 8-point city closed. Since Green was currently ahead by 2 points on incomplete features (8 to 6) and also has a 4-point lead, Green would end up with a 12-point lead that Red's 8-point city can't overcome.
This logic took me about 30 minutes to see, by the way. No way I would get it in real time.
And I am not at all sure it is right.
I'm very curious to hear what you actually did (can't view the boardgamearena link until I play some games there).
+1 merit for sharing an interesting real game puzzle!
P.S. I also don't know how to show an attached image inline. When I want inline images, I put the image on google drive. Then I set sharing to "anyone with link can view" and copy the link. That link by itself doesn't seem to work here, but if you put the long image ID number from the google into the line of bbcode shown below, it does work (replace "zzz" with "img"). I figured this out by quoting someone else's post, so I put the real "img" code here too so you can quote and see it.
[zzz width=400]http://drive.google.com/uc?export=view&id=1-ouXYRvlZGOwFGRYXgnBnOc6MqrCNTUT[/zzz]