Thank you for your reaction to this series as always:) While I can understand your frustration with Akane's actions here, I must say I personally disagree with calling it just flat "stupid". There were just so many factors in this episode that really played against her.
First of all, she's a novice. She's probably never held a real gun before. And now, the life of her important friend is in the hands of a criminal and potential murderer. To top that, there's this sudden unexpected moment of trusted Dominator not working, and that Makishima's Crime Cof. going down to Zero.
She is given a chance to save her friend, but not without a huge pressure.
This is a pure moment of despair and confusion for her. Being in that kind of situation is tough for anyone to respond quickly with right decisions. Not every protagonist can have heroic iron will and guts to do the right things at the right time.