Immolation and Cloud Immunity?

[treerex5]

Had a slightly weird experience today, and I'm not quite sure if this is intentional or not.

I was running around Lair:2 with a scarf of cloud immunity (the only bit of cloak armor I'd found so far), and got the idea to use a scroll of immolation against a herd of yaks - after all, the cloud immunity would mean the fire only hurt them.

Turns out the scarf doesn't protect you from the immolation scroll's clouds of flame. Is cloud immunity supposed to work this way, or did I just get unlucky with a bug? What exactly does the ego protect you from?

[Sprucery]

It should protect you from freezing, mephitic, poisonous and miasma clouds at least. I guess immolation is more like an explosion than cloud...

[Siegurt]

It protects you from the residual effects from standing around in clouds. Immolation causes things to explode in a fireball-like way, and leave behind fire clouds. The damage from the explosion isn't cloud damage, and the scarf provides no protection from it.

[Shtopit]

Yup, it must be the explosion.

Scarf of cloud immunity apparently doesn't exist in 0.25, so I tried with the Robe of Clouds. You get damaged by the initial blast, but you can stand safely inside the clouds.