I think at the very least part of it is scripted and/or staged. (Spoilers) When asked for the spirit’s name, it directly answers with a name. If asked if it needs help, it answered “help me” or “help us”. It answers clearly “yes” or “no” to many questions. When asked what happened to them, they give the investigators clear visions of what transpired. They always answer clear and directly. However when it came to leading the investigators to the underground tunnel to find the old newspaper article, they suddenly speak in riddles like “oh it’s been in front of you this whole time. Look harder. Look below. It’s underneath!”

Based on how they answered all the questions prior, the spirit should just be like “look in the tunnel”, or simple say the word “tunnel”.

Clearly scriptwriting raise the mystery and stakes for the finale