Yes, I don't think Thorin interacted with Bard prior to the death of Smaug in the book. Bard isn't introduced at all until Smaug is about to attack, and isn't named until mid-attack. But that should be all the more reason to take the advice of Roäc, I would think - Roäc wanted a good outcome for the dwarves, was trustworthy, and had a good bead on the situation in what was left of Laketown.