From the outside as no sports law expert, I would have thought the only possible 'negligence' might be if it was expected/normal for warnings to be shouted if a ball was off line by player and/or marshalls. But we all saw the atmosphere, there's no guarantee you would have heard it anyway.
Looks like the woman who has tragically lost the sight of one eye after being hit by a shot from Koepka is going to sue the organisers. The player was clearly shaken up both at the time, and when he got the news yesterday.
But is this negligence or evidence of any wrongdoing by the organisers...