RadiButtonList - client side event goes through on a disabled listitem

Question

I have the following RadioButtonList:

<asp:RadioButtonList ID="rblCordLevels" runat="server" AutoPostBack="true" OnSelectedIndexChanged="CordLevel_SelectedIndexChanged" RepeatDirection="Horizontal" RepeatLayout="Flow" CssClass="hand">
<asp:ListItem ID="liDraft" Text="Draft &nbsp;&nbsp" Value="1" runat="server" Enabled="false" />
<asp:ListItem ID="liPMReviewed" Text="Reviewed 1 &nbsp;&nbsp" Value="2" runat="server" Enabled="false" />
<asp:ListItem ID="liSPMSSMReviewed" Text="Reviewed 2 &nbsp;&nbsp" Value="4" runat="server" Enabled="false" />
<asp:ListItem ID="liPEOALCCCReviewed" Text="Reviewed 3 &nbsp;&nbsp" Value="16" runat="server" Enabled="false" />
<asp:ListItem ID="liApproved" Text="Approved (Final) &nbsp;&nbsp" Value="32" runat="server" Enabled="false" />

In code behind, on PreRenderControl, I set each items disable/enable based on business logic and also bind it to javascript. The control renders fine. However, when I click on the label part of the disabled radiobutton, somehow onclick event still gets to the client and fires, despite the particular element having its disalbed property set to true and being rendered as disabled (grayed out). This does not happen if I click on the radiobutton part though. What is happening here?

Thanks!