I encourage anyone with skin in the game to read the court documents, they are easy to read and really lay out the case for how anti-recruitment agreements (whereby Google agreed not to directly recruit from Apple and vice versa) directly affect overall pay scale. It is laid out clearly, concretely, and isn't just a wishful case. There are a few solid narratives which I think will put google under severe pressure at trial (eg: giving EVERY employee a 10% raise because of Facebook's aggressive recruiting).
First off, it's a FACT that Google's (and other companies) agreements are illegal. That isn't even what this case is about - the DOJ came to a settlement and Google is no longer allowed to make such agreements. This case is about wage impact and class impact. Now that the class action was certified by a judge, there is good chance that in a trial a connection between the illegal activities the companies in question were conducting and class-impact and wages were affected.
Since you used to work at Google, presumably you're a smart person, I hope you can see how your own personal feelings about how recruiters from other companies should or should not behave have little bearing on the actual illegal activities that Google was undertaking.
Now, as a Google employee, you certainly know about the pay bands, right? That your pay is not at the sole discretion of your hiring manager or your manager, but set in a company wide policy that employees of job title X get paid between $A - $B with GSU/RSU/option grants in a specific range as well. There are pay bands for every single title in the company (except maybe executives). Google (and Intel, and many companies) make it a high priority to keep internal equity between employees at given titles (eg: SRE II), so if too many employees were being recruited away and retained they would have to adjust pay, either by giving promotions or adjusting pay bands.
As we know, Google had to elect to do the latter. In response to Facebook recruiting, Google gave across the board 10% raises, and specific raises to SRE titles as well. This is all laid out in court discovery, and is a fact, even Google's lawyers dont deny that.
The class filing has a lot of discovery, a strong narrative, and statistical modeling to demonstrate there was "class wide impact" (aka YOU were affected by your coworkers inability to discover their true worth via getting unsolicited job offers).
Now, finally, you said "some people have argued... shouldn't even be actively be contacting candidates." The question is ... why is this justified? Where's the legal basis for such a strict restriction? Also how does it affect overall market dynamics? Maybe if there was an country-wide law for this, but what purpose would it serve? In a market based economy wages are set by companies bidding for employees. Since a lot of people in this field have jobs nearly all the time, the only way to find out they are unpaid is to be offered a job with a higher pay. There are only 2 ways for this to happen, one is for the employee to seek, the other is for companies to reach out. Why restrict companies?
I think a lot of your arguments are around the notion of definitions of "aggressive", polite or decorum. Legally speaking there isnt any distinction here, and I am not sure the common good is benefited by restricting the function of the market of jobs and employees.