finger inside the trigger guard for the purpose of dealing with the cop, should he prove a threat
See, no. You don't put your finger inside the trigger-guard because someone might prove a threat, you do it because you need to shoot him/her/it and you are doing so. The moment she came out of the ship with her finger inside the trigger-guard and her gun pointed at nothing in particular, she failed gun safety 101, and there's not a single moment depicted where she should have her finger there.