Maybe it has been mentioned, but I wouldn't be surprised if the FBI didn't crack the phone at all. They may have not wanted to go to court because there is a chance that Apple could set a huge precedent. So, if they say they cracked it on their own then it would both make the FBI look like a technical powerhouse and eliminates a potentially damaging case. Apple, in turn, looks bad because it creates the narrative that their OS was cracked without their help.
I'd think the FBI would be touting some kind of information they found on the phone that could have been useful if they had actually cracked it, regardless of how insignificant the information was.