The below code is bad, both javac and intellij complain baout it

public class I {
}

public class C implements I{
}

But in the below code is javac complains, IntellJ not:

public class BadIsGreen7 {
    public void test() {
        I i = new C();
    }
}

D:\IntelliJ-Bugs\badisgreen\badisgreen7\BadIsGreen7.java
Error:Error:line (12)incompatible types