Is it safe to eat this meat? I have a photo.

I purchased Hanwoo brisket through a fast and fresh delivery service, and I took it out of the hot water after soaking it to make soup because something seemed off. The inside part was pink like that, and even after soaking it in water, it wouldn't wash off, and unlike the cooked parts, the pink color didn't change despite the heat. The company's customer service center couldn't even explain exactly what the problem was, but they just said it's fine to eat. Does anyone happen to know what this might be? It's not like they would stamp a Hanwoo seal inside the meat...