disk activity after halt command

[lumpynose]

I'm using a 2 gig usb flash drive that has an led inside that blinks when there's activity. When I halt the system with
$this->bbcode_second_pass_code('', '
# sync
# halt
')
It blinks after the sync and then after the halt I get the dialog box from putty about the session having closed. But then the led blinks for several seconds after putty tells me that the session is closed.

I suppose I should be concerned about pulling the usb flash drive out while it's blinking? Or pulling the power plug? Lots of usb flash drives don't have an activity led so this seems sort of sketchy to me.

This is the PogoPlug E02 model.