C# dynamic issue

Program.cs

class Program
{
    public static void Main()
    {
        dynamic data = new { SomeProperty = "ABC" };

        var response = IsTrue(data);
        if (response == "1")
        {
            Console.WriteLine("How can this compile?");
        }
    }

    private static bool IsTrue(object someData)
    {
        return true;
    }
}