2 things:
People were asking about it, so I checked on GlobalSecurity, and the Pohang class of corvettes (including the ROKS Cheonan) have no ASW of any kind apparently. So yes it would be quite possible for a NK sub to get within firing range unnoticed and escape. They wouldn't have even known about the torpedo coming.
Secondly some people were saying that the fact that the surviving crew was "quarantined" after the sinking is suspicious. It is suspicious, and I said as much at the beginning of the thread. They were quarantined because (and you can check this against the original news articles on the subject) the original SK government line was that the sinking was the result of an accidental explosion. They wanted to try to avoid the mess that would go along with blaming North Korea. Very early remarks by naval personnel contradicted the accident explanation, and so the crew were kept away from the media for some time, probably (and this is my hypothesis) until the military had done its own preliminary investigation. That's the chain of events that I constructed from reading the early news reports, and I think it's fairly obvious.
People were asking about it, so I checked on GlobalSecurity, and the Pohang class of corvettes (including the ROKS Cheonan) have no ASW of any kind apparently. So yes it would be quite possible for a NK sub to get within firing range unnoticed and escape. They wouldn't have even known about the torpedo coming.
Secondly some people were saying that the fact that the surviving crew was "quarantined" after the sinking is suspicious. It is suspicious, and I said as much at the beginning of the thread. They were quarantined because (and you can check this against the original news articles on the subject) the original SK government line was that the sinking was the result of an accidental explosion. They wanted to try to avoid the mess that would go along with blaming North Korea. Very early remarks by naval personnel contradicted the accident explanation, and so the crew were kept away from the media for some time, probably (and this is my hypothesis) until the military had done its own preliminary investigation. That's the chain of events that I constructed from reading the early news reports, and I think it's fairly obvious.