While illogical, I would still think that as a seasoned Huntsman who prides himself on being knowledgeable, he would at least be more aware of that possibility. Maybe he planned to go there later in the week’s trip, but there’s no way to know that now.
Thinking more about it, the ‘lightbulb going off’ idea when he did encounter the hole worked, but it’s possibly just me wanting him to be more aware of the very place they’re in and using the knowledge of its history to explore more. I get I’m delving a little too deep into this. From a purely storytelling point of view, it was absolutely fine.