You can label something an "explicit escape hatch" or a "latent property of the system", but in the end such labels are irrelevant. While I agree that it may be easier to review unsafe blocks in Rust compared to reviewing pointer arithmetic, union accesses, and free in C because "unsafe" is a bit more obvious in the source, I think selling this as a game changer was always an exaggeration.
Having written lots of C and C++ before Rust, this kind of local reasoning + correctness by construction is absolutely a game changer. It's just not a silver bullet, and efforts to miscast Rust as incorrectly claiming to be one seem heavy-handed.
Google's feedback seems to suggest Rust actually might be a silver bullet, in the specific sense meant in the "No Silver Bullet" essay.
That essay doesn't say that silver bullets are a panacea or cure all, instead they're a decimal order of magnitude improvement. The essay gives the example of Structured Programming, an idea which feels so obvious to us today that it's unspoken, but it's really true that once upon a time people wrote unstructured programs (today the only "language" where you even could do this is assembly and nobody does it) where you just jump arbitrarily to unrelated code and resume execution. The result is fucking chaos and languages where you never do that delivered a huge improvement even before I wrote my first line of code in the 1980s.
Google did find that sort of effect in Rust over C++.
