Seals ≠ coins! BIG difference. This is why one can never rely on a regular newspaper to report numismatic news.
Yeah, I have almost never seen a decent article in a regular newspaper about ancient coins. They always get a major aspect of it wrong. I especially hate it when they all of the sudden "discover" an amazing coin, a coin that in reality has been known for centuries. They had an article on a Cleo VII and Antony silver coin abotu 5 years back on Yahoo that made it sound like this was the first one ever discovered.
And this discovery in no way proves that Samson existed, it merely indicates that whoever made the seal was aware of the story assuming that this seal actually represents Samson.