Thank you for this report.
After investigating it, we confirm that this is a bug in the RadTimePicker control and it is logged in our bug tracking system. And we will do our best to fix it in some of our future releases.
As a side note please mind that the "Inline" value for the "DisplayMode" property currently does NOT affect the control on WindowsPhone 8.1, i.e. no matter of the value of the "DisplayMode" property - always the "Standard" mode is displayed. We will update accordingly the help article also.
Your Telerik points are updated accordingly.