Just because something is written in Rust, doesn't mean it's good Rust.

I have noticed, in general, LLMs tend to "fix" problems by shoving them under the rug (like adding a cast) or writing a super-local "fix" instead of taking the time to understand the deeper problem or structure.

In Rust, when you get stuck in a complicated borrow-checking problem, Rust people will tell you it's a Good Thing(tm) because it forces you to think about the higher level architecture of your code. An LLM, on the other hand, might bash its head a couple of times trying to "fix" the problem, and then just throw in a Refcell (or other workaround), see that it compiles, and call it a day.

Refcells "move borrow checking to runtime", meaning that the code will compile, and will crash at runtime if the object is tried to be accessed from two different places at the same time. In most "normal" programming languages it's not an issue -- but it's a crash in Rust.

Now, maybe the models have gotten better, and maybe you can get around this problem by using a good system prompt/"tools" and a good testing methodology. What I am saying however is that you shouldn't automatically take "rewritten to Rust by AI" at face value of it being good Rust code, or a testimonial of "Rust and AI being a good match". (Go is better I think)