What was the point of it? Guts is in the belly of the Loch Ness monster, so how does this "betrayal" and Gambino's advice fit into the picture. It would've made more sense in a future event were it would've been relevant.
Don't get me wrong, the chapter in itself was great. But then again, that was when the manga was at its peak. Berserk as it is now is saturated with monsters and fairy tale elements has declined terribly. It's not as bad as Naruto and Bleach, but then again I expect more of Berserk than I do of Naruto and Bleach.