As for the bill referenced in the OP...
It quite clearly states that it covers recording PRIVATE CONVERSATION between two or more parties where A REASONABLE EXPECTATION OF PRIVACY exists. To whit, simply recording the police going about their day to day business IN PUBLIC (where there is no reasonable expectation of privacy) would not be illegal. Recording the private conversation between two offices, an officer and a suspect/member of the public would be (potentially).
You obviously aren't an expert in law. Try reading the definition of "private conversation".
"(d)Private conversation
For the purposes of this Article,
"private conversation" means any oral communication between
2 or more persons, whether in person or transmitted between the
parties by wire or other means, when one or more of the parties
intended the communication to be of a private nature under
circumstances reasonably justifying that expectation."
In short, all the cop has to say is he intended the conversation to be private, and that's it. The recording is illegal regardless of how actually public it is.
I also found this section interesting
"(Source: P.A. 91-357, eff. 7-29-99; 91-657, eff. 1-1-00.)
(720 ILCS 5/14-5) (from Ch. 38, par. 14-5)
Sec. 14-5. Evidence inadmissible.
Any evidence obtained in violation of this Article is not admissible
in any civil or criminal trial, or any administrative or legislative inquiry
or proceeding, nor in any grand jury proceedings; provided, however,
that so much of the contents of an alleged unlawfully intercepted,
overheard or recorded conversation as is clearly relevant, as
determined as a matter of law by the court in chambers, to the proof
of such allegation may be admitted into evidence in any criminal trial
or grand jury proceeding brought against any person charged with
violating any provision of this Article. Nothing in this Section bars
admission of evidence if all parties to the private conversation or
private electronic communication consent to admission of the evidence."
This section basically states that if the officer DOES decide the conversation as private, instantly any evidence collected in this manner is inadmissible in court. In the past in Illinois they abused laws intended to prevent wiretapping. The supreme court struck this practice down, so now they have modified the language of the bill to explicitly say what they were just interpreting and abusing before. In the past organizations dedicated to monitoring police will often simply disable audio on their devices. You can not catch a cop lying or contradicting themselves this way with words, but you can however still legally document police brutality for example IF THE AUDIO IS DISABLED.