Hello,

Thank you for reporting this behavior!

The button/link in question ("Book Now") is a custom asp:LinkButton control declared in the ItemTemplate of a GridTemplateColumn. As this button is not a built-in part of the Telerik RadGrid but a custom element in a Template, its accessibility compliance is supposed to be handled by the developer like any other configuration in the Template field. 

<telerik:GridTemplateColumn HeaderText="Book" ColumnGroupName="BookingInformation"
    AllowFiltering="false">
    <HeaderStyle Width="102px" />
    <ItemTemplate>
        <asp:LinkButton ID="BookButton" runat="server" Text="Book Now" OnClientClick='<%# String.Format("openConfirmationWindow({0}); return false;", Eval("CarID")) %>'
            CssClass="bookNowLink" />
    </ItemTemplate>
</telerik:GridTemplateColumn>

In case a similar structure is needed for a custom application, you can replace the asp:LinkButton with an asp:Button, or Telerik RadButton, or manipulate the aria-role attribute of the rendered element with some custom code.

The referred Overview demo is designed mainly to showcase a common usage of the RadGrid control with some of its features. To better evaluate the built-in accessibility support of the RadGrid I would recommend using the WCAG 2.0 and Section 508 Accessibility Compliance demo where the EnableAriaSupport property of the Grid is enabled. Find more details regarding the accessibility settings of RadGrid in the WCAG 2.0 and Section 508 Accessibility Compliance article. 

We are currently in the process of improving RadGrid's Accessibility compliance and such feedback could prove really helpful for us. Please do not hesitate to let us know if you face any issues in terms of accessibility with the default structure of RadGrid.

I hope you will find this information useful.

Kind regards,
Doncho
Progress Telerik