At 36:10 Sarah is seen sleeping holding the handheld transceiver with her right hand. After her mother says "it's gonna be alright", another shot shows her holding it with her left hand.
When Mathieus' air hose is burnt through, they don't consider trying to fix it (considering that they are in a science lab) or even breathing from the hose. They also don't think to take the bottle so they have a spare; nor do they try on any of the several suits available in the lab to see if they fit, especially Anna, who isn't much larger than Sarah.
When Mathieu sits up the dead man so he can take off his jacket, the man moves his arm.