VB -> C#: Exclamation point operator treated as member access

[GrahamTheCoder]

Input code

See https://docs.microsoft.com/en-us/dotnet/visual-basic/programming-guide/program-structure/special-characters-in-code#exclamation-point--operator

Should probably have an Imports statement or two:

Public Class hasDefault
  Default Public ReadOnly Property index(ByVal s As String) As Integer
    Get
      Return 32768 + AscW(s)
    End Get
  End Property
End Class
Public Class testHasDefault
  Public Sub compareAccess()
    Dim hD As hasDefault = New hasDefault()
    MsgBox("Traditional access returns " & hD.index("X") & vbCrLf & 
      "Default property access returns " & hD("X") & vbCrLf & 
      "Dictionary access returns " & hD!X)
  End Sub
End Class

Erroneous output

using Microsoft.VisualBasic;
using Microsoft.VisualBasic.CompilerServices;

public partial class hasDefault
{
    public int this[string s]
    {
        get
        {
            return 32768 + Strings.AscW(s);
        }
    }
}

public partial class testHasDefault
{
    public void compareAccess()
    {
        var hD = new hasDefault();
        MsgBox["Traditional access returns " + Conversions.ToString(hD["X"]) + Constants.vbCrLf + "Default property access returns " + Conversions.ToString(hD["X"]) + Constants.vbCrLf + "Dictionary access returns " + Conversions.ToString(hD.X)];
    }
}

Expected output

using Microsoft.VisualBasic;
using Microsoft.VisualBasic.CompilerServices;

public partial class hasDefault
{
    public int this[string s]
    {
        get
        {
            return 32768 + Strings.AscW(s);
        }
    }
}

public partial class testHasDefault
{
    public void compareAccess()
    {
        var hD = new hasDefault();
        Interaction.MsgBox("Traditional access returns " + Conversions.ToString(hD["X"]) + Constants.vbCrLf + "Default property access returns " + Conversions.ToString(hD["X"]) + Constants.vbCrLf + "Dictionary access returns " + Conversions.ToString(hD["X"]));
    }
}