I have expectations while walking that there are no open unattended manholes along the way. What I have seen around here is that warning cones or wood barricades are placed BEFORE a cover is removed. Due care is all we should expect.
Why did all of the crew members turn their backs, briefly or not? How many of those crew members would it take to change a light bulb?
Had she stumbled over or kicked a cone and then fallen, IMO, the crew had taken reasonable care.
The young lady should hopefully learn a lesson, especially as she is near driving age. Also, there are other hazards along the streets and sidewalks.
All of this being said, I don't think the lawsuit should be for much money.
A teen's family plans to sue after their 15 year old daughter fell into an open manhole while she was texting. Apparently the workmen hadn't yet put the safety cones in place. I wonder if it would have made a difference in the outcome.
Glad she wasn't hurt but hope she got a good wake up. Watching where your feet are going to land is a better practice than the faith that the ground will rise up to meet them. (stolen paraphrase of an old Irish blessing)