Out of curiosity, why do you think he'd install Inklet if he has a Mac Mini? 🙄
I'm not sure why Ink would show up... it's kind of weird. Is it still there after a restart/logout? Have you tried removing all of your USB devices and seeing if it's still there?
I have a tablet and the Wacom software installed, and Ink only shows up when the tablet is connected, so it's not the Wacom software that enables it.