What I can suggest in your case is to try one of the following options:
1) Set two tooltips - one onmouseover and on - onclick. In this manner, if the hover tooltip has not been shown, the onclick one will show after the specified delay
2) You can use the OnClientShow event of the tooltip to set a flag. After that you can handle the click and if the flag is not set - programmatically show the tooltip by using its method show() or clear the flag.
I hope that my suggestions are helpful, let me know how it goes.
the Telerik team