That explains the question:
Was it a real trade? Where the trades real? Answer: no
What was it then?
Answer: A software exploit. This could have happened on many different levels. It could've been a SQL Database attack, it could've been an exploit in the website code itself, etc....
What information is this based on? The current "official" story is that read-only database access was obtained through a side channel.
No further information is needed to explain the observed sales. That is simply the effect of filling every single open buy order.
If this were true, as the OP is suggesting and claiming. Then performing the rollback would make the Mt. Gox balance sheet "solvent" but they would be insolvent.
OP, yes, this is all numbers like you say. Yet, if people do not come back to pay their "negative balance" then what you are suggesting would mean Mt. Gox is likely insolvent and cannot honor all withdrawals.
Edit:
Ah, looks like you want the topic closed. Makes sense.