I don't care about the room.
I care about people downloading stuff they have no right to in the name of security, when actually that wasn't strictly necessary to document the fact that there is an issue.
As soon as you shift from showing that there is a problem to downloading data to establish the size of the problem you are the problem.
Whether he disclosed it responsibly or not is besides the point: you don't get to download a database to prove that it could be done, then you've changed a white hat POC into an actual leak and that is a completely different affair.
FWIW this was in Germany against a server in Sweden if I've understood it all correctly and I would bet a sizeable amount of money that I know more about EU data protection laws than you do.
Leaving aside the legal argument and focusing on the technical side: Lovable is a Swedish company, but websites generated by Lovable are hosted on servers around the world. That said, the actual data is stored on Supabase servers, which -- as far as I know -- are located in the US.