I have seen several have problem with this, myself included, figured it out after a while.
You have to burn them the first time AFTER they re-animate. If you burn them when they are not animated you wont get the burn count.
So kill them "normally" first, then use fire when they get back up.
Clarification + TL;DR
Kill them with anything but fire, when they re-animate you burn them.
I used Firewall spec wpn for this.
You have to burn them the first time AFTER they re-animate. If you burn them when they are not animated you wont get the burn count.
So kill them "normally" first, then use fire when they get back up.
Clarification + TL;DR
Kill them with anything but fire, when they re-animate you burn them.
I used Firewall spec wpn for this.