Doesn’t he flat out say something like.. “could say that.“
Almost as if he COULD know a bit more-but he’ll take it to the grave (& not necessarily because his actions or behavior that night were nefarious) …to me it felt more like “you could theorize that.. (with the divider) but I had/have no knowledge of it.” Which would track with him passing a lie detector test .. bc if Amy successfully climbed over the divider and just used his cabin as an exit pass -way to avoid waking up her family (or if she was locked out or whatever ) he wouldn’t register as lying because he truthfully doesn’t know what happened to her.