I'm not completely sure if this is a mistake or not. On the Basculin page you list its abilities as Reckless, Adaptability, and Mold Breaker. In Black 2 and White 2 (according to Bulbapedia) Blue-striped Basculin can actually have the abilities Rock Head, Adaptability, and Mold Breaker (Red-striped have the same abilities that you have on the page). Apparently a Rock Head Blue-striped Basculin is also obtainable through an in-game trade in White, but wasn't available in the wild or something.
Also, presumably for the same reason, the page for Rock Head doesn't mention Basculin under pokemon with that ability.
Here is the Bulbapedia page for Basculin
Here is their page for Rock Head, which gives some more information about Rock Head Basculin at the bottom of the table.