Yeah, but Scattershot Guy wasn't waiting behind Nib as he spawned. He came from the right as Nib reached the top of the stairs and more so, you can see him coming in the motion tracker.
Edit: Nib, you're making yourself look bad. You ran up the stairs and met an enemy who was canvassing for victims. You're at fault. He didn't fall out of the sky on top of you. SMH
I was going to mention this too, a normal reaction to a red dot coming towards you shouldn't be meeting him head on in Close quarter, is take step back until you can see him visually, if you haven't seen him and he did see you, he is in advantage, so you need to move away.