I'm not going to vote until you correct your grammar:
The correct way to spell it is
1. Satoshi's an individual who started bitcoins on it's own.
Options
1. Satoshi is an indivudual who started bitcoin on his own.
2. Satoshi is a group of indivudual who started bitcoin together but under the same name.
3. Satoshi is a project group in NSA who started bitcoin with the ambition to test an on-line currency that easily can be monitored
He got it right the first time; your correction is wrong. It is "his own" and it's is short for "it is"; which would not make sense. "Its" shows ownership to "it" so that would be more correct but in this case the reference is back to Satoshi, therefore making it "his". Texting kids these days...
If you are not sure then at least don't correct other people.