I believe the article links directly to a PDF copy of the USA v. Matish decision housed by the EFF: https://www.eff.org/files/2016/06/23/matish_suppression_edva...
It's also worth pointing out (because the article makes a hash of things), that the case involved two different issues: expectation of privacy in the IP address, and expectation of privacy in the contents of the computer.
The opinion is here: https://www.eff.org/files/2016/06/23/matish_suppression_edva.... The discussion of the IP address issue starts at 43, and the discussion of the privacy issue starts at 47.
The first decision is reasonable: no matter how you try to obscure things, an IP address is public information. Some third-party must have your IP address in order for you to receive packets.
The second decision is, of course, unreasonable. Saying you have no expectation of privacy in the contents of your computer because it can get hacked is like saying you have no expectation of privacy in your house because it can get broken into.
I suspect that on appeal, the former decision will stand and the latter will not.