The Overwatch Public Test Region allows players to play on an updated version of the game that contains role queue matchmaking, several hero buffs and nerfs, and the ability to play as Sigma, who is Overwatch Hero 31.
The post contains a video of a Moira player defending against an attacking team on Eichenwalde point C. Knowing that the enemy team is going to make an offensive push with a teamfight initiation ultimate, such as Reinhardt's Earthshatter, the Moira player hides behind cover in order to stay safe. Despite being outside of the Earthshatter's line of sight, she is still knocked down from the ultimate.
According to several users, this strange interaction has been in the game for a long time. In the video, the Moira player was hiding behind a staircase that was perhaps only two meters above the ground. As such, it was possible for the Earthshatter to travel up the staircase and knock down Moira in the process. However, the point still stands that the Moira player was outside of the Earthshatter's line of sight, and she technically should not have been hit.
Hopefully, the Overwatch team will look into this problem, and perhaps address it in a future update to the PTR.