Despite the evidence, the Danites chose to reject God's Word. What mattered to the men of Dan was that the priest told them what they wanted to hear. Better yet, he had said it in the name of God. Most of us don't strike out on our own, heedless of guidance. It's not difficult to find someone like this, but don't trick yourself into believing you're hearing the Word of God.
Faith comes from hearing the message.
What they found was a land like the promised land, but the people were easy, soft, and isolated. Danites put them to the sword and settled there. No, God didn't tell them or anyone else to conquer this city. Three times they're described as unsuspecting, twice as peaceful. The text implies an injustice done.