User blog comment:-Chloe-/Merlin's Story/@comment-5515850-20120916160548

Merlin was LYING to Arthur. The Great Dragon said that only Merlin could restore Arthur's faith, as the dragon is a Seer. So Merlin decided to lie to Arthur, and said Bruta's sword was stuck in the stone, when in fact MERLIN had forged and enchanted the sword with the dragon's help and put it in the stone. So it was in fact a fluke. I had to watch the episode numerous times to understand.

Bruta is not related to Arthur, and the sword was never Bruta's sword, being recently forged.