He probably thought he was invulnerable like everyone else who gets caught. It does boggle the mind a bit. He should've done a runner a long, long time before.
I think you hit the nail on the head. He was way too cocky in his own cleverness. I mean reading the Wired article of the FBI agent's account of events shows he was over confident. On the day of the arrest the agent realized too late he was walking right past Ross looking like a cop, carrying a laptop, and Ross didn't even notice him. I mean, come on.