Well, I don't have Diamond, so he couldn't have been playing that one. On the other hand, Pearl wasn't in the DS, either. What was in the DS were Kirby Canvas Curse and Pokemon Leaf Green down in the GBA slot, so take your pick, I guess. And no, I never have seen that missing Depth Carge. It probably went to the same place all the left socks do that never emerge from the dryer.