I found a copy of the full order at http://www.conjur.com.br/dl/decisao-whatsapp-vara-criminal-d... (source: http://www.conjur.com.br/2016-jul-19/juiza-manda-suspender-w...).

To me, the most eyebrow-raising part is "[...] além do encaminhamento das mensagens já recebidas pelo usuário e ainda não criptografadas [...]" (page 4, rough translation: "and also the forwarding of messages already received by the user but not yet encrypted"). Do they believe that the messages are encrypted only after being received either by the user or by a central server? I get the feeling that they think that the encryption is done by a central server, and that the messages can be intercepted there before the encryption (while in reality, they're probably encrypted by the sender's phone, so intercepting would mean pushing a software update).