Given that almost all early iPhone OS and iPhone have bugs and vulns that allow jailbreaks and carrier unlocks, it's completely unsurprising that the NSA had a 100% success physically.

For example, iPhone 3GS released in 2009 can be jailbroken with 2010-era latest iOS 4: http://www.iclarified.com/jailbreak/iphone3gs/mac.php?firmwa...

I don't think you even need baseband access to do all the spying. I think all of that can be done on a jailbreak.