Yes it was a typo. Paul's code applied the character style to the existing text of the control. To apply it to the control itself, you need to extended the start and end range by 1:
Code:
Sub Demo()
Dim oRng As Word.Range
Dim oStyle As Style, oControl As ContentControl
Set oStyle = ActiveDocument.Styles.Add("RTCCStyle", wdStyleTypeCharacter)
With oStyle
.QuickStyle = True
.Font.Underline = wdUnderlineThick
.Font.UnderlineColor = wdColorBlack
.Font.Italic = True
.Font.ColorIndex = wdRed
End With
For Each oControl In ActiveDocument.ContentControls
If oControl.Type = wdContentControlRichText Then
Set oRng = oControl.Range
oRng.Start = oRng.Start - 1
oRng.End = oRng.End + 1
oRng.Style = oStyle.NameLocal
End If
Next oControl
End Sub