Shortly before 34 minutes in-Darby crushes 1 of 3 pills, but there are 3 intact pills during the snort scene.
Sian's helmet is running out of oxygen, and now it won't unlock. Rather than dismantle it, Andy decides Sian needs a quick tracheotomy! But the helmet's rubber flange sits comfortably against the flesh of Sian's throat, and sliding even a finger underneath would break the seal and provide airflow.
Despite having the building under constant surveillance no one ever check any footage for whom was near the lab around the time the morphine was stolen.
Darby should be able to eliminate suspects by analyzing the size and weight of the person who attacked her and layed on top of her.