Nope. The government does not have to disclose investigative techniques. If Apple wanted to help the government, they could have, but they chose not to take that tact. Expecting the government to help Apple now is folly.

What about Cellebrite thus www.cellebrite.com. This article seems to suggest it is them - http://gizmodo.com/the-company-helping-unlock-the-san-bernar...

Why would the company used have any responsbility? Remember, the phone is owned by San Bernadino county. They wanted it cracked. The holder was the San Bernadino Sherrifs', they want it cracked. The FBI wants it cracked. The judge issued a warrant covering the data on it, and then the all writs act compelling companies to assist if they can.

Apple could not.

Cellebrite could.

I get what you're saying, but this is having your cake and eating it too. Apple chose not to assist. The FBI found someone who could. Why would that company then have to disclose to, basically, a third party (even a third party inventor of the phone) their standard work product and trade secrets?

Would it be possible to make a FOIA request?

Until the next case comes in, where the FBI says that what they tried last time didn't work.

The EFF's Andrew Crocker suggests that the "Vulnerabilities Equities Process" (the result of a previous EFF lawsuit) might legally require them to reveal how it was done: https://www.eff.org/deeplinks/2016/03/fbi-breaks-iphone-and-...

Regardless of the legal requirement, others (and likely Crocker) don't think that this is that likely to happen, though.