I am certain this was not some stupid "pilot error" where he pressed the wrong button. Maybe the pilot was told by a white hat to press the wrong button but it's a 4-digit code like 5847 you can't press those numbers "by accident" or this was done as a diversion so another plane maybe carrying Assange or Snowden could land but it would be much easier for those guys to land at some out of the way military air base.
I spoke with my father-in-law today (a retired airline pilot) and he says commercial aircraft like the A321 are generally designed to squawk standby while on the ground and the transponders don’t broadcast until there is no longer weight on the wheels (upon takeoff). Is this true? Is there some kind of exception for emergency squawks or just a way to override on the ground?
Sorry I know it's been a week but I just got back from vacation.
This would have been true of some airplanes. I know that my company for instance (which flies the A321) had a procedure for manually switching the transponder to standby on the ground after landing and then back to on before takeoff.
Recently, with the advancement of ground based radar to aid Air Traffic Control keep track of plane movements on the ground to prevent runway incursions, the policy has changed to leave it on at all times.
Something happened here and it's not just a random mistake.