At Conviction's White Box Labs, Sam rescues a scientist from the Black Arrow mercs. The scientist explains what's going on, and lets Sam into the elevator. Sam tells him to get out, and the guy says he'll hang around, because his friends might need him. He's willing to face take on armed, elite mercenaries for his coworkers. And maybe because he knows they've been working on a weapon. Or both. Doesn't really matter.
This little dialogue at the end of Conviction:
Victor Coste: He talked about learning who was really important to you, and why you always had to come back for them. He talked about family. And you know what the last thing he said to me was, just before he hung up? "Vic," he said, "Thanks for everything. I love you like a brother." Brother. That's family right? *Alarms go off and gunshots are heard* Victor Coste: Yeah, I thought so.
During the Seoul mission in Chaos Theory, the player is required to call in an airstrike on a downed jet to prevent North Koreans getting some important data aboard it. The player is then told to leave the pilots to die in the blast rather than make several incredibly risky trips past a tank and a few soldiers; saving them, however, prompts Sam to say some pretty heartwarming stuff: