FBI 'walks back' official story

Josh Voorhees has a Slate article about the Boston Marathon bombers:

So now we've gone from "had a knife" to "maybe had a knife" to "nope, no knife." The Washington Post has the latest information out of Florida, where the FBI has still not gone on the record about exactly what caused an agent to shoot and kill Ibragim Todashev while he was being interviewed about his connection to Tamerlan Tsarnaev:

A Chechen man who was fatally shot by an FBI agent last week during an interview about one of the Boston bombing suspects was unarmed, law enforcement officials said.
Initial reports citing anonymous law-enforcement individuals provided conflicting accounts of what happened. Some law enforcement officials said Todashev wielded a knife, and others suggested that he attempted to grab the FBI agent’s gun.
One law enforcement official, speaking on the condition of anonymity to discuss an ongoing investigation, said that Todashev lunged at the agent and overturned a table. But the official said Todashev did not have a gun or a knife. A second official also said Todashev was unarmed. An official said that according to one account of the shooting, the other law enforcement officials had just stepped out of the room, leaving the FBI agent alone with Todashev, when the confrontation occurred.

Unnamed law enforcement sources (maybe the same ones; maybe not) tell a similar story to Orlando's WESH, although they add the detail that: "Sources said Todashev might have been lunging toward a sword, but he was not in possession of it." That, obviously, would change the story signficantly— although it would still come up well short of the original version of events that had Todashev, knife in hand, lunging at an officer.
The FBI has so far provided only the very broad outline of what happened in Todashev's apartment the night he was killed, saying that the shooting occurred "when a violent confrontation was initiated by the subject." The Bureau says that the full investigation could take months. Until then, the law enforcement officials being allowed to talk off the record are free to continue to change their story with little if any repercussions. (While it won't make the FBI look good, it provides the officials at the top plenty of cover to hide behind.)
For posterity's sake: the knife detail was originally reported by The Associated Press, NBC News, and ABC News, among others. (The New York Times, meanwhile, had it as "a knife or a pipe" or something).

Rico says hide and watch on this one...