You had a 50/50 chance of getting it right. It sounds like things were done right based on your test. I'd always take the precaution of shutting off the power to the fixture prior to changing bulbs, etc... anyway.

How did you verify the screw shell was not hot?

He put his tongue to the screw shell and turned the switch on.
He posted the message, ergo he wired it correctly.

I almost forgot. While his tongue was contacting the screw shell, he placed the little finger of his left hand on the grounding conductor in the device box. Then he closed the switch.

I had a coworker who used to regularly test for hot wires by licking his thumb and then touching the conductor. I can't say I ever tried that myself.