It's being applied, try to use the flamethrower with the acolytes that teleport on the last map (just before the alien ship), if you do it correctly you will be setting more than one acolyte in fire, I've tested this myself before just posting the reply <!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt=":)" title="Smile" /><!-- s:) -->.