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.
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.