hes not trolling, flames do normal damage to units in cover, but they ignore any cover bonuses. also since units tend to bunch up in cover flamers will hit a lot of models at once.
OK. I thought I had seen Cruzz say that flames do "normal" damage in open cover, less damage in red-cover, and extra damage in green cover and houses. Maybe it's just units are clumped in green cover and once the house catches fire, all the units start take damage...