There are obviously security bugs in Apple's code, almost certainly some which allow for breaking into a device. That's even more likely to be true because the

There are obviously security bugs in Apple's code, almost certainly some which allow for breaking into a device. That's even more likely to be true because the device in question wasn't fully updated. However, the situation as I see it is this: The FBI realized they were going to lose their legal battle to compel Apple to unlock the phone in question. They then retracted their suit to avoid a precedent being set against them, and announced "don't worry guys, we got in anyway" to deflect attention from that particular iPhone, which they had argued was where the situation would end in the first place. Your explanation is certainly possible, I just don't think it's as likely that they would really spend $1m on this phone which in all likelihood has nothing of value on it to begin with.