If Daniel has nyctophobia,,,

[MrWhitticus]

I didn't quote it, I just summarised it. But no, he didn't fear the dark, he feared never being able to escape it:
- "He wasn't particularly afraid of the dark, but he had always disliked going into the basement. His father urged him on to fetch the red dye. As he stepped into the dark, he thought, "I will never escape this""
- "He cried like the little boy he was. All alone in the dark basement, broken glass tearing at the flesh of his naked feet, and blood mixed with blue tint."

He didn't like the dark back then. He always had a fear of being trapped in the darkness forever, and I guess you could say that the incident in the tomb triggered it. My point is just that he developed the fear earlier. I agree that the incident must have been very traumatising to him, especially if he never really liked the dark.

Plus there's a possibility that maybe the effects of his phobia had moved on by the time that he became an archaeologist and that may be a reason as to why he decided to be brave and venture into a run down tomb that could collapse at any point and trap him.

A very thought provoking point.