I don't think he made a difference to the difficulty either. I remember when I saw it late and gave it a try for the fun of it, it was only at difficulty 2 or 4? Keep in mind the difficulty doesn't go up if he doesn't have the hash power to generate more than 1 block per 10 minutes on the average.

Since he took about 2 months to generate about 580K coins, we're looking at around 6042 blocks over almost 1500 hours, or just over 4 blocks an hour. At that rate, difficulty won't go up. So if 0.5TH/s jumped onto ixcoin at the start, we would had seen the same thing.

Fortunately for ixcoin, there was supposedly only 100~200+ GH/s for several hours to drive up the difficulty without causing too much problem.

This also reminds me of another factor, i0coin is targeting 5 minutes per block, so the block generation speed effectively doubles for the same hash power.