Am I missing something or is that bold claim obviously wrong on its face? This seems like a Go deficiency (lack of atomicity for it pointers), not some sort of law about programming languages.

Can you violate memory safety in C# without unsafe{} blocks (or GCHandle/Marshal/etc.)? (No.)

Can you write thread-unsafe code in C# without using unsafe{} blocks etc.? (Yes, just make your integers race.)

Doesn't that contradict the claim that you can't have memory safety without thread safety?