I have worked in the US and now am in South America. In the country where I live, if you have a work contract, then you definitely have more protections in the US - guaranteed paid vacation, paid holidays, paid maternity leave, etc. Independent contractors/freelancers not so much, although getting health insurance was easier/cheaper than in the US when I freelanced, at least.

As far as what happened with your co-workers, I am sorry to hear that. They may have not wanted stick out their necks, as others have said. There was a woman I worked with who wasn't offered an indefinite contract after her probationary period. She was a really sweet person. I did wait a few days to let her process things and then called her to say I was sorry to hear what happened and wished her good luck in the job search.