I can assure you that memory leaks specifically and resource leaks generally are possible in any language more expressive than a stack machine with an arena.

Rust makes an interesting and demonstrably pragmatic set of tradeoffs here as opposed to e.g. C/C++: treating std::move as a default (aka linear typing) prevents a lot of leaks. But it still has pointers (Arc, etc.) and it still has tables: it’s still easy to leak in a long-lived process doing interesting things. For a lot of use cases it’s the better default and it’s popular as a result.

But neither Rust nor k8s have solved computer science.