I think this is a vanilla bug, but I noticed in singleplayer JA, Stormtrooper variants don't play their custom death sounds (bodyfall_trooper1-4.mp3) defined in the model's "animevents.cfg" file.

This affects the NPCs:

• stormtrooper2
• stofficer
• stofficeralt
• stcommander
• rockettrooper

They all use the same "playermodel", but the sounds only seem to trigger for the base "stormtrooper" NPC.