This is in fact true. There were (are) multiple people using the login to bitcointalk.org.
Satoshi Nakamoto was a group and at least three people from the group held the BTC login.
Your story is showing some cracks. Bitcointalk.org didn't exist until several months after satoshi's last login.
Last Active: December 13, 2010, 04:45:41 PM
Creation Date: 2011-06-24T05:19:00Z