I don't if they are or not and I don't know what process the FBI is using to track people down.
I can think of several reasons. Maybe the FBI has already identified them and is still in the process of drafting indictments. There are new ones coming out every week.
I do know it's an illogical leap to go from "the FBI isn't handling this the way I imagine they should" to "those guys were FBI agents".
It's cliched but true; extraordinary claims require extraordinary evidence. A FBI false flag is an extraordinary claim and this guy provides nothing in the way of evidence.
It shouldn't be discounted out of hand though, simply because an FBI agent(s) hasn't been indicted over it or we haven't seen HD video of FBI agents in full uniform in the act.
Slowly, more and more (at a minimum) circumstantial evidence is coming out.
There is smoke. We shall see if there is any flame.