Do this now — one minute

  1. Change your password at myaccount.google.com/security. Not because we kept it — we didn't — but the habit is worth having.
  2. Confirm 2-Step Verification is on while you're there.

Three things gave it away

The one rule

Never sign in through an email link. Open a new tab and go to the site yourself. That single habit defeats all three tricks above, and you don't have to inspect anything to use it.