No code review by default goes against actual established evidence (there is little of this for software development practice) that code review is the best way to find defects.

I always get the impression from using hardware and other anecdotes like this that it is rare for hardware companies to know how to do software development well because their core competency is hardware. In fairness, it is uncommon for software companies to know how to do software development well.

Every form of testing has its value when done well and they are using several forms that most software developers don't use- probably helps make up for the lack of code review and unit tests. But if they incorporated code review and unit tests their software would likely be even higher quality.

Property based testing is amazing, but it won't provide full coverage. Regression suites are amazing, but generally the most expensive form of testing in terms of time to write and maintain tests and time to run them.

Today AI can crank out unit tests so its silly not to have them.