#1: The I-Just-Forgot-You-Killed-the-Other-Twelve-Guys-in-my-Gang-Just-Now Syndrome

To trigger this, walk right in, blow away lots of people, throw as many grenades as you want ... then sneak briefly.

Raider - "Huh, what's that?"

Me - "It's me, uh, sorry for killing all those guys. I just moved a step just now - that's what you heard. I'll stop moving for a sec and crouch down."

Raider - "Uh, must be hearing things."

Me - "Uh, no - pretty sure you heard those dozen deaths, the 40 unsilenced shotgun blasts, and the 4 frag granades. Not your mistake. I can actually see you. You just walked over some dead bodies. Bodies that I killed. Just now."

#2: Stuff Dropping from the Sky

To trigger this, just walk near water.

Eventually you may hear a splashing sound - repeatedly. Took me a while to figure it out, but random stuff will just fall into the water. From the center of the sky. Heaven. Sploosh!

#3 Suicides

This shouldn't be a spoiler, but there is a group of Gunners who are chilling out on top of an overpass. The overpass is way-way-way up high.

To trigger this, shoot at one of them.

Lead Gunner - "Blast 'em!"

Splat, splat, splat as 3 of them fall almost directly upon each other. Dead. At the bottom of a huge jump.