April Orenski's actions in Episode 3. For the past two episodes we've seen her play Drill Sergeant Nasty to Hastati Squad, such as shooting Laskey at the end of their exercise in episode 1 and making Vickers and Laskey give her their quiche for making them have to wake up early that morning. In episode 3 in the midst of the evacuation we see her calling for Hastati in an urgent, motherly-like tone instead of the yelling that she's done throughout the rest of the series. After Hastati gathers around her she takes time to speak calmly to them and reassure them that they're going to be fine and all that they're doing is going up on the tether. It's a nice bit of humanization, showing that she's not just Hastati's commander, she's also their friend and Cool Big Sis too.
In Episode 5, Master Chief is willing to take on a Hunter with nothing but a single grenade to give the cadets time to escape. When telling his comrade over the radio to keep the Pelican around until they can make the evac point, he firmly declares that he won't leave them behind.
Also, when they come under sniper fire, the first thing the Chief does isn't return fire, but put himself between the cadets and the incoming shots.