An error should occur when a static method in an interface is invoked via an expression qualifier (rather than unqualified or via a type).

public class StaticInvoke {

  interface I {
    static void m() { m(); } // ok
  }
  
  void test(I arg) {
    I.m(); // ok
    arg.m(); // error
  }
}

javac already implements this error check, but the Lambda Spec does not include it.