The whole $1k mark was based on phantom deposits, and holds of that exchange making it to retain so high compared to other exchanges.
The bubble was real, a simple bot would never be able to do all of that. There was real people buying and selling 1K USD/BTC, mixed with manipulated automation. Bots are everywhere in the stock market those days anyway.
The bot was able to do it. I believe it accounted for about 10% of the total volume on Gox at that time(!!!) At first that doesn't sound like much, but just imagine: 10% of just buying coins and never selling any. The buying pressure created by Willy effectively cut the inflation (due to block rewards) to 0.