The fight only gets more impressive the more you watch it. Hoshoryu actually looked kinda panicked once he realised that there's nothing he could do to get Dan off him. I think the reason he's so immune to being pushed down because he's actually so close to his opponent that they simply don't have the leverage to push down on him with any real force. You either keep him out the way Onosato and Daieisho have done it, or you're basically done for because he IS going to take out one of your legs eventually.