The Monster has Impunity

[Erik Sigra]

> The net effect of these three forms is to say that a monster has a 90%
> chance of hitting a building and causing 1 hp of damage; three such hits
> destroy the building. A monster's knuckle might occasionally be skinned
> doing this; a 10% chance of 3/100 hp damage is not usually dangerous, and
> feels a little more realistic without complicating things for the player.

This text in the Game Design Manual Tutorial implies that the monster
can get hurt when attacking buildings. But I destroyed very many
biuldings withoud ever loosing any hitpoints. Is something wrong?