I hesitate to demonize 8ch solely on the basis that they require legal protocol to be followed. I expect all organizations to require warrants before handing over data to the authorities.
I'm more inclined to believe that this FBI agent is not familiar with standard operating practices, seeing as his biography describes him as spending most of his career working on drug gangs, which is a somewhat different beast than online domestic terrorism work.
Relationships aren't really with the organization (RE the 4chan comment), they're more with the individual agents and pretty decentralized. I've never had the same FBI agent twice, for example.