In Diamond and Pearl Versions, Lass Madeline mentions having gotten a Badge from Oreburgh, which implies that she did defeat Roark. That would be close to impossible, considering she has only two Pokémon (Starly and Bidoof), both of which are at levels below that of Roark’s Geodude (his weakest Pokémon) and having only moves that are resisted by all of Roark’s Pokémon.