Somehow bc.i showed a fake tx. How? Whats the tx hex? Wat this signed properly? etc etc.. May questions.
Somehow bc.i was disconnected from all of the nodes they had previously been connected to. Then an attacker proceeded to perform a sybil attack by attempting to make sure that bc.i's node was connected only to the attacking nodes. The attacker then created an orphan chain starting at block 1 and fed that to blockchain.info. Then they included several transactions which spent the early coins and made it seem as if Satoshi had moved his Bitcoin. Since many people use bc.i, they were tricked into thinking that Satoshi had moved his coins.
What I posted above is absolutely what happened, but is what I think is most likely to have happened.