While I think it’s a troll account, it is technically true that the rules around unsafe Rust are a little harder to get exactly right to avoid UB because you still have to uphold the much larger surface area of rules in safe Rust without any of the compiler help. C++ by contrast of course has fewer such rules and they’re easier to reason about but of course there’s no compiler warning when you violate them.
On the other hand that line of argument is kind of weak sauce because the vast majority of bugs aren’t in complicated recursive data structures. And you can always implement doubly-linked list in pure safe rust just with slightly more overhead by using Rc/Arc if you wanted guarantees (and you can also verify the unsafe implementation using Miri which is a significantly strong runtime checker than c++ where you only have ASAN/UBSAN)
The whole discussion sucks, because Rust is not memory safe, and can easily be worse than C and C++ regarding memory safety. Memory unsafety is entirely possible in Rust[0].
And the prevalence and difficulty of unsafe means both that Rust is not memory safe [1], and that Rust sometimes is less memory safe than C or C++.
[0]: https://rust-unofficial.github.io/too-many-lists/
[1]: For an example of memory unsafety in Rust: https://materialize.com/blog/rust-concurrency-bug-unbounded-...