The third one was three noble acts in one. Mayday takes the bullet for Crosshair when an avalanche came to their direction, Crosshair tries to save Mayday instead of letting him go and avenged Mayday’s death by killing Nolan. In other words, Crosshair cried “mayday, mayday” for Mayday.
Very hot take: I found Tech to be very angry with his brothers for being nothing but disobedient because his eyes squinted, and then when he fell, I speculate that he felt happy because he finally found peace. I didn't notice any sorrow in his face, or at least an "I'm sorry I have to do this."