I can't be defending the statements of whoever says this, but I do think that the reasonable way to understand it is that the fundamental model that the Rust compiler and standard library attempt to implement is safe and correct by construction, rather than as a statement about the concrete implementation.

Among software developers, we shouldn't need to provide a "assuming there are no bugs" caveat with every statement about how something works, because we know that bugs are essentially unavoidable at scale. We can say that Rust makes it much easier to avoid bugs, but nobody serious has ever claimed that they are 100% eliminated.

It's not like C or C++ compilers are bug free either, despite implementing much weaker models.

> the fundamental model that the Rust compiler and standard library attempt to implement is safe and correct by construction

This comes up a lot as a defensive argument too, but it's also pretty frustrating, because Rust's "fundamental model" is not a thing that really exists. There are project proposals to create one (such as https://goals.rust-lang.org/2026/roadmap-project-zero.html#), but at the moment it's just a vague set of vibes people gesture towards to dismiss all the problems with Rust-as-actually-implemented.