Quite tellingly, you make no denial of the main accusations. The question is not whether this was your idea, but whether you were telling the truth when you said that your website was 100% not affiliated.with Starbucks.
No, that's just a sideline, a thing people are investigating as to proof to the actual main question, whether or not this is a viral campaign sponsored by Starbucks. He quite firmly denies that.
No, because time is a consideration. If SBUX jumped on the bandwagon to sponsor it after it became a big hit. Because he could be telling the truth as at the point of the card's creation, it was just a hobby project of his and SBUX knew nothing about it.
The main question is whether he is affiliated with SBUX in any capacity, because that's a statement he made from the start and it's provably true or false.
My guess is that the truth is somewhere in between. That it was a hobby project. But that as Starbucks is a client, he figured getting some goodwill from them through it would be frosting on the cake. He didn't intend to make money directly, but obviously, if it was a success, SBUX's benefits and so does Stark's company, indirectly.
The card had been active for more than two weeks previous. My guess is that a project that is intended to be a mass-viral ad would not wait for someone to randomly submit it to HN.