Whether the platform was mobbed or not - and this one likely wasn't given the time of day - no straphanger is going to think of the subway as a jobsite where one shouldn't wear loose clothing. Nor should they.
Maybe they should not need to, but safety begins between your ears.
If you can anticipate all possible freak outcomes, you can prevent
most (not all) accidents.
A fraction of a second is all it takes to ruin your day.
I have seen it too many times in 40+ years on drilling rigs, and I'm always paying attention.