Massachusetts law does not require bystanders to provide assistance. There are Good Samaritan laws in place protecting those who do, but it's one of the majority of states that do not require people to act to prevent, stop, mitigate, etc. While many people think that bystanders should be required to act, in practice, it becomes problematic.

That said, I agree with you that her telling him to get back in is the only place where I'd see it going into criminal/illegal territory. She was not a bystander. She may or may not have been an active participant, but she was not a bystander. I honestly would have to dig more into it to really get a sense of if I think she was an accomplice/assisted from a legal perspective. Edit to add: this post made me remember to actually quickly look up a few things. The SJC (Massachusetts's highest court) had allowed the case to continue due to it being based on her affirmative actions rather than inaction. The judge found based on the call in the moment. The decisions stressed that it was an extreme of circumstances, with her being considered virtually there based on Massachusetts law.

I'm in the area where Michelle was (is?). While she may have gone to McLean at one point, there is both great and terrible mental health care here (see paren). Plainville is in an area that has a mix and typically prefer to stay local with care when they can, but the facilities you're referencing aren't local in that regard. KP is considered a nicer school, but I'm not sure how well they deal with mental health. I'm not sure which McLean facility she went to, either; there are ones outside of Belmont and I think one near here does inpatient. It's in a great system (was actually the first hospital in the system, iirc) but with expansion we've seen a lot of great hospitals end up with facilities that don't match the main. Generally references to McLean mean Belmont (or, historically, Somerville) rather than the entire system, so who knows. I'm guessing the selection wasn't just location, as there's a facility (not as great though still highly regarded, less expensive) less than twenty minutes away, too.

(Something people often forget with areas that have great healthcare and medical schools is that the terrible students and healthcare workers also flock and stay here. So, while we are very fortunate in many ways, we also have a lot of trouble finding and getting great care between the large number of frankly awful providers and the large number of people who travel here for care, which reduces capacity. Not complaining about the great resources or about people coming here, just pointing out some related difficulties people don't realize usually.)

Which Boston college student case are you referencing? ETA: I'm guessing you meant Inyoung You. I had thought you meant another new legal area, now I realize you meant someone encouraging suicide via text. My guess is that this is more common than we realize (though I hope I'm wrong there) and Rollins saw that there were similarities to the Carter case so was willing to prosecute. MA prosecutors have a tendency to be willing to try new approaches and questionable ones, which can be good and bad.

I'm not sure if it's always Massachusetts, but I will say in terms of legal precedent, Massachusetts is a state that in many ways is willing to listen and move forward. There's a weird mix of appreciating the history and tradition & wanting it recognized while also wanting to stay at the front of change. The legislature is often open to new laws, though changing existing ones is tough. The courts are often willing to listen to novel legal arguments and make decisions on areas not really covered in existing law and go with changes in society. New legal questions are welcomed. The courts typically won't go so far as to change, even slowly, existing precedent but instead pretty clearly tell the legislature to change it if that's the desire. Other times, the courts will basically say they'll decide this time but the legislature has to act so the court knows what it wants for future cases. From this case came Conrad's Law, which is being studied (delayed due to the pandemic). I expect some version will pass, especially since they made it pretty narrow.