To boost this online, make sure to have a friend to help. We did it in Ranked, but I'm sure player will work too. For the Hunt Scene, we did the Elimination gametype and had to wait till the 6th round for the Infected scene to show up. Just sit still for a while and wait till the timer gets to 0:04 and run up and touch your friend, then just back away and you'll get the achievement in a few seconds.