A billion times more complex than the safety-critical parts of an airplane? I think you lack perspective on avionics packages and the safety measures that are undertaken in that industry. Additionally, I think you're vastly over estimating how complex a smartphone is.
A billion might be hyperoble (although i dont think its a totally unreasonable guess either), but phone software is many GB large, i could easily believe that there are a million more MC/DC points in phone software, than in the safety critical part of airplane software.
