There's some huge differences there. A daylight stroll through there with at least two other people is not even close to the nearly pitch black trip SG took through there. They could see the path they wanted to take to get to where they wanted, SG couldn't even see her next footfall while heading towards the only glowing source of light she could see. The moon was barely into the first quarter and so close to setting that it was way low on the western horizon making that area as close to blacked out as possible. Everyone who saw and heard her said she was panicked, disturbed etc., whether it was drugs or her mind, and it's very possible between panic, exhaustion and the elements, she died. The way the timeline doesn't really leave a moment for anyone else to have gotten in there and be involved makes what's very possible very probable.