I really doubt the FBI was there on a bogus child-porn charge. That's more of the purview of local county governments eager to use their DHS-grant surplus military assault rifles. The FBI isn't going to misinterpret context like some six-tooth sheriff's deputy (the FBI would like to stick to entrapping Muslims and Occupy sympathizers with fake bomb plots, thank you very much).
So either the FBI was there, and it had nothing to do with child pornography, or they weren't, and it was another police agency. Or 2 is just making it all fucking up.
(fun story: once upon a time, a relative worked in a department of a major company whose scope included security. This company employed engineers locally, including one multi-decade employee who was of Iranian origin, but had come here either before the Revolution or in its immediate aftermath. A few years following 9/11, a few bona-fide FBI agents showed up at this local office wanting to talk to the guy. In their post-interview discussion with said relative, they pretty much told him that they had received a bullshit "tip" - they knew it was bullshit, probably a racist neighbor or something - this guy lived in a really nice part of town - but policy at the time dictated that they had to follow up, regardless of merit.)
If it did actually happen, the way it's told has too many unanswered questions and doesn't make sense, so it could be he's drumming it up for theatrical purposes, kind of like Mike Daisey and his Apple Factory story on NPR.
That's actually an appropriate analogy, considering pretty much everyone involved in that thing was a jackass. Not only did Daisey ruin a perfectly legitimate cause (the very real plight of Chinese workers) for his own stupid self-promotion, but he was aided and abetted by O.G. existential wanker Ira Glass, who subsequently used to the faux controversy to wail about "facts" and "storytelling", when his show is nothing but upper-middle class people telling us how deep and meaningful their lives are.