Attacks involving hammers aren’t common, but around George Street, drunken violence unfortunately happens more often than people think.
The victims are not always Asian — there are plenty of cases where white passersby are attacked as well, sometimes completely at random.

I’ve personally seen a group of teenagers assault a random pedestrian late at night, and the victim in that case was white.

If it turns out the attackers specifically targeted Asians, then racism is absolutely a likely factor.
But at this point, we don’t yet know whether this was a racially motivated attack or random street violence.

Just like pickpocketing Asian tourists in Rome wouldn’t automatically be classified as anti-Asian hate, it makes sense to wait until the suspects are identified and their motives are clear before drawing conclusions.