为什么这不会在VBA中产生类型不匹配错误？

Question

我将一个变量声明为HTMLAnchorElement对象，该对象是为html“a”标签保留的。然后我将变量设置为段落标记，该标记应仅适用于HTMLParaElement对象。不管怎样，变量变成了一个副元素，尽管另有声明。

Option Explicit

'Turn on references to Microsoft Internet Controls
'and Microsoft HTML Object Libraries before running

Sub qstn()

    Dim IE As New InternetExplorer
    Dim el As HTMLAnchorElement

    IE.navigate "www.youtube.com"

    IE.Visible = True

    Do Until IE.ReadyState = 4: Loop

    Set el = IE.Document.getElementsByTagName("p")(0)

    MsgBox TypeName(el)

End Sub