Rust compiler assumes that unsafe code still follows the borrow rules and optimizes code based on that. So if that is not the case, the consequences can be bad.

Rust compiler assumes that unsafe code still follows the borrow rules and optimizes code based on that. So if that is not the case, the consequences can be bad. For example, there was a bug in Rust OpenSSL bindings where OpenSSL had not documented the proper life time of some of the function arguments/return types. As the result unsafe code containing the call to OpenSSL C implementation violated Rust memory model leading to crashes. But I agree that such problems are rare in Rust and Go races are much more problematic.