This aged like milk. :(
Do they know how far away they were? What rooftop they were on? I'm hoping they get away with it, but I'm not sure it would even have to be monetarily motivated. Maybe one of their friends or family members were killed as a result of his bullshit? There's plenty of reasons to kill a shitstain like Kirk. Plenty of people, especially on this website, would've done the same if they had the ability.