afaik Satoshi went "dark" when government reached out to Gavin for questioning. And since creating any form of money by a citizen is prohibited, it doesn't surprise me he did just that.
I find this somewhat weird:
1. Creating any form of money by citizen ends the citizen up in jail.
2. Developing said 1 further does not end up citizen in jail ?
Too funny.
Could be a trap for him though:
1. Legalize bitcoin.
2. Wait till he spends coin.
3. Then say it was all a big fat joke/lie to trap him ! =D
There's a big difference between the time bitcoin was created and now, altho even now it's not cristal clear as to what bitcoin should be referred as legally.
Satoshi backed off because the future was unclear, and he didn't want to risk it.
Regarding your trap idea, well, i doubt government would go into such an extent just to make an arrest, there are better ways to do that.
cheers