When does assist count as kill

The only solution I see here is disable the speakers/headphones and set the communication headphones as default and set it as the only device that can be used, and see.

You can change it back once you are done playing, but at least you will enjoy your game.

High Value Target is a default commander resource featured in Battlefield 4. It reveals the location of an enemy to the entire team for 45 seconds, becoming available once that enemy has reached a six or more kill streak. Bonuses are awarded to players who eliminate HVTs, and to HVTs themselves for continuing their kill streaks.

Ref: http://battlefield.wikia.com/wiki/High_Value_Target_(Commander_Resource)