In the Entity class the move(double, double, double) method calls an EntityCombustEvent if the entity combusts due to standing in fire or lava based on the return value from World#f(AxisAlignedBB). I understand that there is not really an easy way to grab the associated block that does the damage as quite a few locations are checked when the call to f() is made and it only returns a boolean but I would prefer the correct event to be called with a null block rather than a generic combustion event. This behavior would then be consistent with the combustion event is called in Entity#burnFromLava().