Either way, it's a little bit of deception but wouldn't be grounds to walk away.
Just because you're angry?
Can you see that he didn't see it as an existing condition, if didn't register with him.
Why not sit down and have a cup of coffee with him, before you make your decision?
Well, then - don't buy a house, build one.
The disclosures, while well-meaning, in my opinion aren't really worth the paper they are printed on in most cases. Could you walk away from the deal? Possibly. Do you want really want to, or do you just feel deceived/angry? People purchase homes all the time without disclosures for anything. The point is that it seems like you are more "angry" over the sellers "deception", than you are the consideration of "Does this fact really affect the condition of the home at all"?
I would trust the results of the home inspector who should be working in your corner, more than I would I piece of paper the seller signed.