wrong

premined is a term for where coins are released WITHOUT mining  (pre-mine)
satoshi's coins where created VIA mining..

secondly. the code was released publicly and if you look at the hidden techy stats of the blockchain. you will see that multiple people were mining it. and yes that includes hal finney mining it in the very first days

thirdly although between 2009 and 2012 although 10.5 mill coins were mined. meaning in year one 2.5mill coins were mined. guess what. satoshi was not a third of the population in 2009. there were actually dozens. so the 1mill coin number is not accurate. even the nonce analysis shows this