It very well could have, if it weren't pulled off the exchanges (i.e., protection kicked in). Really, 8% is a very serious portion of any economy. Any bank would go belly up if people attempt to withdraw 8% of it's money in one day.
And selling hacked money vs. actually selling bitcoins is absolutely the same from the exchanges point of view. Supply was overwhelmingly larger than demand, getting new money in takes several days, so it is absolutely clear to me - what happened and why it does not prove any weakness in the BTC economy. Just a poor exchange protection.