Something like that. I don't know whether physical magazine and digital raws come out at the same time or not, but yes. Your conclusion is correct. They probably had someone from Japan scan the magazine.
To be clear, they had someone in Japan
steal the magazine from the supply chain (delivery driver, printing house worker, something) and then scan it. The physical magazine goes on sale at the same time as the digital one does. (In actual practice, the physical magazine comes out about 5 hours later, since the digital magazine goes on sale at midnight and most retailers don't put the magazines on their shelves until about 5am).
I read an interview with a manga artist who said how sad he was when he'd open Twitter a couple days before his manga came out and overseas fans were already talking about plot points, meaning that pirates from the West got to know what happened before his legitimate customers did.
Pre-release translations hurt the industry. Don't support them.