The manipulator's walls aren't creating panic, and he isn't pushing the price down to buy, because there is very little buying going on. If they are profit taking, why not remove those ask walls, let the price rise then dump for better profit? So I'm going to go out on a limb and say its an idiot kid who mined 10s of thousands of btc on his gaming computer in 2011, is bored since school is out for the summer, and he is the only one laughing as he keeps the bubble from commencing. I say this because no smart person would still be putting up sell walls for no benefit.
Two possible scenarios:
1) Obvious sell wall is usually put there to test the market. If it is lifted very quick, buying back the same amount of coin and pay a little extra premium and wait for the coin price to go up.
2) The person putting up the sell wall want to buy bitcoin below that price. If there is no buyer, he can keep lowering the sell wall to buy at cheaper price.
Or a combination of both.