Using even the published demo code at demos.telerik.com, I cannot shift-tab out of a toolbar control. This can be reproduced at http://demos.telerik.com/kendo-ui/toolbar/index: get the focus inside the toolbar and press tab to go forward through the buttons, eventually exiting the toolbar and on to other items. Again, put the focus in the toolbar and use shift-tab to move backwards through the elements. The focus reaches the first button and stops - it won't shift-tab out.
In my product's code, I experience almost the same, except the shift-tabbing seems to stop at the second button in the toolbar, not the first as seen in the demo.