This kind of problem is bad, certainly, but not terrible. There may have been some confusion regarding pricing that kept some people out of the market, but at least their ability to trade wasn't impacted like it was in Tokyo.
If there's little trading, that would be quickly reflected in the shares.
When you have this kind of problem, it calls into question the entire system. As an investor, you question whether the liquidity in that market is there, whether you can buy or sell exactly when you want to. And maybe you decide to sell off your stocks if you don't trust the system.