Ok, I can confirm it now, as I've just seen it in-game:
Ammo explosions cause injuries separately from torso destroyed/head hit.
I just got pilot incapacitated result on a Locust from one salvo of LRM20 + LRM10: torso destroyed, ammo explosion and knockdown (leg was destroyed to I think).
Ammo explosions cause injuries separately from torso destroyed/head hit.
I just got pilot incapacitated result on a Locust from one salvo of LRM20 + LRM10: torso destroyed, ammo explosion and knockdown (leg was destroyed to I think).