If, for example, someone convicted of sexual assault decides to give an interview without permission, and proceeds to reiterate the details of the crime, that would undoubtedly harm the victim of their crimes. That is what I meant by the safety and needs of a prisoner not being the only concerns.
SBF didn't sexually assault anybody, but the rules exist for such reasons, and SBF breaking those rules surreptitiously doesn't make it okay. The first concern, I imagine, was "how the fuck did that happen?" which meant assessing the damage.
Should he have been thrown in solitary for 24 hours? Probably not, but should he have been isolated from his room and other prisoners for 24 hours? Probably, while they assessed what had happened and how.
If he had snuck contraband in (a smartphone), then that would have been, for example, a real safety issue, since smuggling in contraband doesn't end at cell phones, and the pathway doesn't change. Initially, it was not clear how it occurred.
That's all I'm saying. I know the slippery slope argument, and I agree with it, and I have previously read the Senate Report on Torture, and do not disagree.