"Would be great to get to the bottom of this."
Ah, well, the thing with RV is, you have to have feedback.
And the snag here is, there could actually be multiple reasons for the phenemena you are interested in.
The thing is, as a project, you are asking people to voluntarily set up a blind situation, many times, where viewers have to experience cattle and human mutilation, using different feedback photos and similar cues.
I don't think that's the sort of thing Courtney Brown would be totally OK with, quite frankly. Let alone the people that view for him.
If you are asking me... well, the term itself is somewhat revealing. It's about post death trauma to a corpse.
The corpse, being a corpse, isn't going to have a problem with trauma, in the sense of no longer being attached to their former vessel.
Others would dispute my reasoning. However, I would note that Daz Smith no longer does Missing Persons cases due to PTSD.