No software is perfect. Not even the one which flew Boeing 747, thats why they had 3 services coded by 3 different teams running on 3 different brand processors and the system takes the 2 matching entries as the truth.
Even micro processors are not immune to long running bugs.
Picking one small thing and demonising a whole team is unfair for them and the company.
That would be Airbus flight controller - concern was over their new by then fly by wire control system so this was used.
The US Space Shuttle had the same concept with 4 computers that ran on the same codebase and hardware from IBM that would check each other on critical components (engine burn/flight control) and if one differed it was voted out.
There the issue was radiation induced memory corruption as the software was top tier tested and verified to be bug free as possible (they used ADA)
Even micro processors are not immune to long running bugs.
Picking one small thing and demonising a whole team is unfair for them and the company.
Sounds like much ado about nothing.