I'm just trying to work this out ....

He's supposed to have had 7500 coins and he mined them in a week on his laptop back in 2009.  At one block every 10 minutes each generating 50 coins that's 300 coins an hour, 7200 coins a day and 50400 per week. 7500 of 50400 is 14.88%.  Now maybe I'm being dumb and I've made some stupid mistake but if I haven't it does not seem credible to me that he had about 15% of the hashing power mining bitcoins back in 2009.

M