Weren’t we originally told not to believe the reports that North Korea had torpedoed a ship?
If it wasn't one of ours, the military was probably caught totally by surprise, and they would never admit it was a foreign missile. The political fallout would be tremendous, and they always fear that the public would panic. Besides, even if they knew a foreign sub was in our waters, what would they do? The might track it, but they wouldn't sink it and a missile launch would probably be the last thing they would expect.
The only recourse for them now is to invent a story that allows "plausible deniability", but they haven't done too well at that either.
Yes, we were. By a number of the same posters that are pushing the magic contrail theory, in fact.