Does blue Teemo trigger twice when revealed on defense (once for being played from hidden and once for defending)?

Ruling: Teemo only triggers once when revealed on defense, not twice.

Nuances:

• If the opponent has a unit with a move trigger (like Travelling Merchant or Drummer), you can reveal Teemo while that trigger is pending but before the showdown begins, allowing Teemo to shoot the moving unit. Then Teemo triggers again when the showdown actually starts, resulting in two triggers total in this specific scenario.
• This double trigger only happens because Teemo is revealed before being considered a defender (during the move trigger window), then triggers again as a defender when showdown begins.