I think it could also just indicate a lack of arbitrage being executed that keeps the price in line with other exchanges, meaning as a separate market the price is free to move higher / lower than other markets without necessarily indicating some sort of problem at the exchange. Normally this would be sort of synchronised to some level by arbitrage.
It seems like the arbitrage opportunity here is real and at least someone recently managed to profit ~10% from it:
https://www.reddit.com/r/BitcoinMarkets/comments/7kitks/arbi...
Although of course it is a bit slow which exposes you to lots of risks, so if you really wanted to do it you would need to hedge your exposure with other types of trades (shorts, etc) to try to limit the amount of risk.
I guess what I am thinking is just it could also be the exchange is operating fine, people are able to withdraw fiat, but it's just not worth the risk / effort to run arbitrage (or people just aren't doing it) and that could at least explain some price difference without there needing to be some sort of systemic problem at the exchange. There of course could be.