So, not 100% sure on original answer, but…
Nerves of Steel:
“When the fighter is hit by a Ranged Attack…”
Shooting: “
There are several ways in which a model may make a Ranged Attack against an enemy model, most frequently by performing an action that allows it to do so, but certain skills and gang tactics will also allow various models to make a ranged attack outside of the game’s normal sequence.
Whenever a model makes a ranged attack against one or more enemy models, this sequence is followed:
- Assess Target Priority
- Declare the Shot: “choose a ranged weapon the model is armed with”
- Measure Range
- Make the Hit Roll: “a hit roll is a ballistic skill test”
- Resolve Hits
Spatial Psychosis:
“Choose a single enemy fighter within 12" of the Psyker, that is Standing and is not Engaged. That fighter immediately becomes Pinned.”
——
So, from that, I’d note that Spatial Psychosis does not require steps 1, 2 (in the sense the fighter is not ‘armed’ with a weapon called ‘spatial psychosis’) and 4, which are the steps which constitute a Ranged Attack.
There are of course ranged attacks which also miss a step (e.g. Template weapons) but the rules for template weapons explicitly state which steps they miss out.
Are there examples of explicitly named ’Ranged Attacks’ which ignore the usual step-by-step process for a ranged attack?
If not, I’d say Spatial Psychosis is not a Ranged Attack, and so does not trigger Nerves of Steel.
If so, then yes rules need clarifying.
My gut is (and I don’t recall if ever come up against this) it is not a ranged attack, and does not trigger Nerves of Steel.
And from a narrative point of view, being Pinned is supposed to represent being knocked of your feet by an unexpected shot, or ducking out the way of a near shot. Nerves of Steel represents being a hard case who takes the shot without being knocked over or being unphased by the fire. Spatial Psychosis however represents a psychic attack confusing your senses and making you lose your sense of balance. Being so hard, or so stupid, that you don’t duck doesn’t affect that.