Refuting elements of theories posted by clueless bloggers or attacking the credentials of others posting alternative theories doesnt validate the official probe. It seems a lot of people want to give the SK probe the benefit of the doubt, and accept its conclusions unless proven otherwise. The opposite is more reasonable; north korea is innocent of this incident until proven guilty beyond any reasonable doubt.
IF this investigation had been conducted thoroughly, transparently, by a team of experts that was above any suspicion of bias, its conclusions might live up to that standard. As it is however, the investigation team is anonymous (!), the credentials of its members unknown (for all I know its composed of hand picked war mongering intelligence people and weapon manufacturer CEOs), from countries that are anything but impartial and the report is a very far cry from irrefutable proof. It seems we are now going as far as arguing whether or not its conclusions are even feasible?
Here is how I see it: an undisclosed team of SK government endorsed "experts" from SK's allies concludes the cheonan was destroyed by an underwater explosion resulting in shockwave and bubblejet, despite the South korean sound engineering expert team that had access to all this data concluded the exact opposite and claimed no bubblejet occurred but a direct gunpowder explosion. The probe concludes the remains of a torpedo allegedly found on site perfectly matches secret schematics of a torpedo that North Korea sells for export (to whom?) of which no other evidence seems to exist. The probe somehow concludes the sheer presence of the torpedo wreckage proves a causal relation with the sinking of the cheonan and doesnt even consider the possibility this export product was exported to a third party country. Members of the investigation team appointed by the SK government that are qualified and had access to all evidence but dont share the view endorsed the the SK govermnemt, are removed from the team and subsequently silenced and even prosecuted. The prime suspect (north korea) is not even allowed to review the evidence.
How would this look in court?
AFAICS, every option is still possible. Yes, it could have been a NK attack, endorsed or not by its leaders. But it could just as well have been a covert false flag operation in line with the current administration's policy to implode the NK regime, where SK not only obtained the torpedo plans, but the torpedo itself. It could have been an accident as suggested by Chin. It could have been a mine. Or a friendly fire incident. It could even have been a false flag operation by a third party that would like to see further measures taken against NK (the US, Israel, possibly even China). Or any combination there off (an accident covered up by using a NK torpedo the south acquired earlier).
Speculating which of those is possible or more probable might be fun, but essentially irrelevant (and without direct access to crucial evidence, probably impossible). What is relevant is that (nuclear) war might break out over an unproven allegation.
Lets hope the Russian and/or Chinese investigations shed some more light on this before this spirals out of control. Too many wars have been started over insufficient or even fabricated evidence.