The claim is not there is no data races in Java programs. The claim is that Java programs are memory safe, because the underlying virtual machine memory model is free of data races.

Go does not have that.

(Of course also Java may suffer from memory safety issues on system boundaries to unsafe code and due to JVM bugs.)

I don’t know Java or the JVM, but if it’s anything like the CLR/.NET, this would either be compiled to atomic operations, or throw an exception.