Why didn't Niko kill both?

[Gettin up]

Niko could have killed both in the mission Blood brothers

Two questions
Why didn't he kill both and walk away without the pressure?
Why did Francis trust Niko that much?

[Silver]

Why would Niko choose to kill them both when he already didn't want to kill Derrick for Francis anyway?

 

As for your second question, Francis foolishly thought he had Niko under control because of the dirt he had on him. Francis even threatened Niko of putting him away if he didn't comply as seen in the cutscene. Obviously Francis was overconfident, and well, you can either prove him right or wrong.

[Encyklop]

The reason why Francis didn't trust Niko that much is beacuse most likely he knew about his days in yugoslavia and he knew he was working with criminals, dealing drugs for them, weapons, etc.

Also another reason is that he spared Clarence (optional in Holland Nights) and he lost trust in Niko after he found he was hanging out with Derrick.

As for the killing for both brothers, idk.

[nearmiss1992]

I was thinking the same thing but I guess the game wanted the player to make a choice