Artillery duels between land and sea units

[Nevill]

Usually, when two artillery units attack each other, there is an artillery duel that ends with the death of one combatant. However, there is one exception to this rule, and that's when a sea unit and a land unit engage in such a duel - only a few rounds of combat seem to occur before the fight concludes. It is therefore nigh impossible to sink a ship from the land or to blow up a land artillery from the sea.

Every other attack in the game results in death of one of the combatants, with the exception of a) bombardment (an artillery unit attacking the non-artillery one) and b) disengagement, both of which are explicitly stated in the rules.

So - should there be another exception, or is it a bug?

[Nexii]

Noticed this too, I feel like it's a bug.