plug mouse in and just factory reset it. if that doesnt work get a mi rom package from online and install it on usb and just do it by the steps.
Plug in an USB keyboard
The Google TV has a single button on the device to toggle and select in the recovery menu.
I assume you've tried the Volume Up/Down and Source on the tv itself?
I haven't encountered that so my suggestion might not work at all. But I would try plugging a keyboard into its usb see if it lets you select stuff.