certain individuals have reported that they believe people who exploited a bug or simply just mined the crap outta the gold mine obtained vast fortunes and knew that a potential money wipe was on the horizon, so they took the loss and converted all their money into glyphs, because they sell back is high, and glyphs weigh nothing.
they could have been the lucky person to find a stack while someone was trying to send that stack to another character by dropping the stack, and relogging on with the other character.