At what? And how do you know?
Good is also relative. If you suck, and he beats you. You'll think he's good. In that case, good could just mean he doesn't suck as much as you.
I took a friend around to find schools in HK a couple years ago. He had 4 years total MA experience under a teacher who only taught him
chi-sau and hard sparring, and he was able to easily dispatch Jerry in
chi-sau, hitting him with the same thing 4 times in a row.
Does it mean anything to get hit in
chi-sau? Sure, maybe not, but 4 times in a row with the same thing means he was unable to learn and adapt. He couldn't cope with a guy with 4 years experience who hadn't even learned the forms, didn't even know they existed...
This was also after he reluctantly agreed to roll a few times after refusing to allow him to do any sparring or even
chi-sau with his students on "sparring night" because they "
might freak out if they did something they weren't familiar with" (a red flag that they don't actually do any serious training).
And it was also after he and his buddy Mark identified his rolling style as Yip Chun lineage (he wasn't even sure of his lineage) and shared little condescending smirks with one another, then preceded to get hit 4 times in a row, with the same thing...
So I'd say his
chi-sau is not very good from what I saw firsthand, and this video shows he doesn't know how to spar either. Not surprising, considering "sparring night" to them means "open
chi-sau".