Sounds like a bad keyboard to me. Your description of not being able to see key presses and the like sounds like a modifier key is stuck. Same goes for clicking on an icon and getting its properties.
It's possible, but the clicking was done with an external mouse, and there's other general weirdness when he's having problems other than just input oddities.
I left him again with a working computer. I told him that if it starts happening again to give me a call. I want to see what the task manager is saying when this stuff happens, but the problem was not recreatable on the spot, and when I got there he was logged out so there wasn't much diagnosis I could do.