Should the player find the Antarctica before Decker gives the mission, the "Yes, he says you betrayed the fleet" and "I have my orders" options should not be available, given that the player may well have no idea who Decker is in the first place.
Related but not a glitch: Should you use those options, the Antarctica will return you to your ship and immediately open fire with lethal intent. If the intent is to give the player a chance to reconsider and flee, Arco Vaugn's AI could be repurposed instead.
If the player has no idea who Decker is, the first answer should be No. If that player instead says Yes, well consequences count.... (or hurt in this case)
The response is "Yes, he says you're a traitor to the Fleet". The player would not know this.
Fixed in 1.9 Beta 1.