Doesn't surprise me. The FBI, I think, is through with dealing with crackers with "kid gloves" anymore, and it's just not a good idea to mess around with them. When this guy saw that the webpage was hacked, he should have just let it be -- he opened the suspicion on himself by poking around. Most people don't start port probing a site just for fun. Some do, yes, but most don't and that's exactly what a cracker does. Ergo, he's under suspicion since the site was hacked that very day.
The one part that struck me: He mentions that they were intent on seizing his computer before they talked to him. Well, duh, Sherlock -- do you think they're going to say, "Oh, he just told us he didn't do it -- let's go, fellas"?