And this isn't one of those mistakes in character, like when Martin forgets an eye colour, or an unreliable narrator like Sansa's kiss - this one is just a mistake.
Here's the relevant text, from the second-last Cersei chapter, from the torture of the Blue Bard (real name Wat)-
"His father had been a chandler and Wat was raised to that trade, but as a boy he found he had more skill at making lutes than barrels."
A chandler doesn't make barrels - chandlers make candles. It's coopers who are responsible for barrels. I can't imagine any way this could be a code or something otherwise meaningful, so it looks like it's just something which slipped by Martin and his various editors.
Here's the relevant text, from the second-last Cersei chapter, from the torture of the Blue Bard (real name Wat)-
"His father had been a chandler and Wat was raised to that trade, but as a boy he found he had more skill at making lutes than barrels."
A chandler doesn't make barrels - chandlers make candles. It's coopers who are responsible for barrels. I can't imagine any way this could be a code or something otherwise meaningful, so it looks like it's just something which slipped by Martin and his various editors.