The bug used by that repository [1] isn't the only one that can be used to escape the Safe Rust type system. There are a couple others I've tried [2] [3], and the Rust issue tracker currently lists 92 unsoundness bugs (though only some of them are general-purpose escapes), and that's only the ones we know about.
These bugs are not really a problem in practice though as long as the developer is not malicious. However, they are a problem for supply chain security or any case where the Rust source is fully untrusted.
Moreover, if I remember correctly, they all are made possible by a single (long-standing) compiler bug that eventually will be fixed.
Previously discussed: https://news.ycombinator.com/item?id=39440808
I think this mindset is the big difference. We're not perfect, but we're working on it.