This discussion won't lead anywhere, as you'll be set in your opinion and we will be set in ours. Which difficulty level did he play? Regardless, all I can say is that for someone's supposed first walkthrough, from what I looked at he seemed quite knowledgeable on where to go, not to mention that right from the start he was running from place to place, hardly looking around.
[added] I see you posted around the same time I did. 
Not having unlocked another difficulty just means he hasn't completed the game from start to finish (assuming the version he has can do that, maybe it can't?), it doesn't mean that he hasn't played already most of the game before this walkthrough. [added]
Currently Playing: Shin Megami Tensei: Devil Survivor Overclocked, Professor Layton and the Curious Village
Anticipating: Xenoblade, The Last Story, Mario Kart 7, Rayman Origins, Zelda SS, Crush3D, Tales of the Abyss 3DS, MGS:Snake Eater 3DS, RE:Revelations, Time Travellers, Professor Layton vs. Ace Attorney, Luigi's Mansion 2, MH TriG, DQ Monsters, Heroes of Ruin
