Very good, and handled excellently.
Something similar happened once to me years ago in the Shibuya train station here in Tokyo. An extremely agitated young guy was physically preventing his girlfriend from getting entering the station, and while he was not actually hitting her, he was manhandling her, attempting to drag her away. They must have been coming back from a ski trip because she was carrying her skis in a shoulder bag with a roller bag for the rest of the stuff. She was crying, but not saying anything.
Hundreds of people simply averted their eyes while they walked past, but I stepped in between them in one of the moments when he had let go of her. Similarly, I wasn’t aggressive toward him, but simple refused to get out of the way while giving his girlfriend a chance to leave. Mr. Asshole was challenging me, but I just calmly told him he was staying put. Another guy also joined me and it was pretty much Game Over.
After the girlfriend had entered the station, we stayed guard for another little while to make sure she had a chance to get on her train. The boyfriend regained some composure and apologized for the trouble – sort of a Japanese thing, and it ended well.