TAU rules question (I know, right?)

[Paul]

Alright, here's a weird rules situation.

1) A Devilfish (Devilfish A) is chosen as a dedicated transport for a Firewarrior troops squad.
1a) Therefore the Devilfish is in the Troops FOC slot.
2) The Gun Drones disembark from the Devilfish.
3) As per the new FAQ, the Gun Drones can contest objectives.
4) These Gun Drones are from the Troops slot, and are Infantry models.
Conclusion: The Gun Drones score.

Which premise is wrong?

Also note that Mech Tau are largely unaffected by the death of the Ethereal as they are no longer required to take the test if they're in a transport.