In the instance that LordKano reached out to them, they were acting as an agent of the company he was applying to, not the company he currently worked for (even if they had an ongoing relationship with that company). By discarding a qualified applicant, they unethically prioritized their relationship with another client over the company they were supposed to be acting as an agent of in that instance.

Unless you have special knowledge of the contracts signed, you really can't say that. It's likely the second company was well aware of the restriction. And it seems like the OP felt he was wronged more than the second party.

If the companies had a contractual agreement that their recruiting agency would block each other's employees from applying, that sounds like a non-poaching agreement of the sort that Apple and Google were fined hundreds of millions for.

I'm pretty sure they weren't fined. I believe they were sued and settled with no admission of wrongdoing.

Ah, you're right, I was mixing up the DOJ action (not involving a fine) circa 2010 with a later civil suit [1]. In any case, it cost them hundreds of millions.

1. https://venturebeat.com/2014/05/23/4-tech-companies-are-payi... (adding to the confusion, Venture Beat incorrectly calls it a fine)

There are so many recruitment agencies in this town that I am not disadvantaged by not working with them.

Their behavior wasn't ethical. They didn't approach me. I found their job posting and approached them.