Okay after rereading it, I'm beginning to think what's happening here is that you are not buying a bomb before you go on the mission. Did you go to the house of haggle before you went to the mountain? And then did you read what Hobs says about what to buy?
You have to have a bomb in order to get through that ice wall or else you fail the mission and have to start over. I thought it made it kind of clear if that's even what's happening here.