The FBI said its budget figures for Sentinel don't include the cost of government personnel, which is factored into the higher numbers.

WSJ: FBI Files Go Digital, After Delays and Cost Overruns

Audio experts Tom Owen and Ed Primeau, who analyzed the 911 recordings for the Orlando Sentinel, said they don't believe it is Zimmerman who is heard yelling in the background of one 911 call.

CNN: STORY HIGHLIGHTS

Even if Tehran didn't have the capability to replicate the technology used in the Sentinel, Iran could sell the drone to China or Russia, countries that would have a far easier time replicating the drone's technological secrets.

WSJ: Iran Says It Shot Down Unmanned U.S. Plane