I found this article to be a good summary of what's going on with the FBI and their inept bungling. If true, it'd be pretty funny that Issa was more technically savy than the FBI.
But even with all of this, it's still dependent on human frailty:
More importantly, this technique wouldn’t work at all had Farook used a complex alphanumeric passcode. The weak link in all of this has been Farook and his poor choice of security.