I think this was all done by one large player who had been holding for some time and wanted to sell at a higher price. So he bought out everything from 10-12c and created an illusion of 13m buyers in the depth so other buyers will line up and sellers are less likely to sell.
Then just before he dumped his stock, he pulled out his large buy orders.
Then just before he dumped his stock, he pulled out his large buy orders.