The FBI is only talking to this guy because he made some noise, not because there is something to the tip. This guy got ticked off because he thinks he is so important the FBI should have called him back, pronto.
That's not how tip-lines work. It's not a "conversation". You call. You leave a tip with some desk jockey. End of story. They don't call every tipster back with a blow-by-blow of their investigation of the tip. But that is exactly what this guy expected. That the FBI would personally have an agent call all 5,000 people who called in tips.
I've only had a tip-line call me back once. And that was for clarification of an exact address. They don't call you back. They don't even ask for your contact information half the time. They log your tip. Flag it for follow-up. And they get to it when they get to it, depending on priority.
The fact that this guy expected a personal follow-up call from an FBI agent is absurd.