http://www.pokemonworldrpg.com/t3961-bruce-mathers-chapter-6-revenge-of-the-game-changer
If you read what he said, that's because he already defeated two Gym trainers and that means he earned himself a little spot of light to guide him around the dark gym of Dewford. He just left after that battle to heal and now he's back to finish this... depends if he'll have to take another break again before fighting Brawly. Thanks.