All damage is inflicted to a single trooper.
p. 137 TW:
"Once the number of hits has been determined, roll once on the appropriate Hit Location Table and apply all hits to that location as separate damage groups (such damage may result in multiple critical hit rolls when damaging a target)."
In the case of 'Mechs, the separate damage groups clause may result in additional Critical Hits or MechWarrior Damage. It would also interact as separate damage groups with regards to Lamellor-Ferro Fibrous armour.
In the case of Battle Armour, the separate damage groups clause has no additional effect unless you use Battle Armour Critical Hits, in the upcoming ATOW Companion.