Korra Alone - S4-E2
Continuity mistake: There are several inconsistencies between the last scene of the previous episode and the one recounting it in this episode: 1) Korra is jumping up and down when she says "Is that all you got?" in the last episode, but in this one, she's standing still, 2) Korra collapses after the line "We have a winner!" is heard, instead of before like in the previous episode, 3) Korra's bag changes design, from a grey duffel bag to a green backpack.
Answer: We do not see what happens. Avatar shows rarely have people killed on screen, so either he got away and was never seen again, or just died right there. As Amon was outed as a bender, he would not go back for his old boss.