I was trying to understand it from both sides and not getting much. Some of your color helps too (like the euro amounts). It all was bizarre and sadly the whole thing blocked some progress.
I had come back to temper my response because for sure this is great work by the tech team.
Some more colour is that the OSM Buildings project didn't even ask permission to use the OSM mark. If they were a community project, this was permissible. If they were a commercial project, they ought to have sought permission from the OSMF.
Given that, it seems pretty reasonable to me that the OSMF's stance was basically: your name is your problem, if you think someone is infringing on it, it's up to you to enforce it.
The OSMF runs on a shoestring budget - something like $400,000/year, vs Wikimedia Foundation, which runs on $170,000,000/year. It would be a real shame if a potential donor thought this particular instance was a reason not to donate to the OSMF.
I had come back to temper my response because for sure this is great work by the tech team.