That something is called bystander effect and is key to explaining the horrendous things humans have been doing to each other for Millennia. It also explains why some bystanders prefer not to remember such incidents… The memory is a fickle thing.
And it is most importantly the reason why discussing such public violations of human dignity are crucial, not just for the sanity of the victim, but also for a better society in general.
Have you never been in a situation when you witnessed the unacceptable and struggled to speak out because you didn’t want to isolate yourself from the apparent safety of the group condoning the not ok? In my experience failure to intervene makes public acknowledgement of the event near impossible. So Jett’s reaction is rational within her own context.
Finally, too many people who have nothing to gain, and who are independent of each other, are corroborating the story for it not to be in core true.