Another Logic Screw Up

I was still on my mage doing some mining and the local quests when I did the Bombs Away quest. This has you collect 8 bobs from round and about and then plant the, 4 at a time, to blow up horde demolishers.

Well, I think they changed this quest half way through development and then forgot to update the quest text appropriately.

I reckon, the originally intended for you to bring the bobs back and then go off on another quest to plant them, but then put it all into one quest. Why?

You'll see in this completion text that the bombs look particularly nasty? What? I've already used them to bob the demolishers!