That didn't seem like a good hand at all at the beggining. Also, making that guy get a royal straight flush doesn't make him seem smart nor capable. In fact, it doesn't tell me anything about him at all. He might be as dumb as a brick and that won't make his chances of getting a good hand any higher.
Im glad the author is so kind as to set the reader expectations very low before making him go through his work, sometimes it takes a lot of time to drop a manga that is going downhill, yet this one already tells me how bad it's gonna be with a delighfully terrible representation of poker and a bent sense of logic (in a manga that, im assuming, is all about logic).