I may be too old, but I think the father can test the waters with his kid in a similar fashion to how I was introduced to programming: simple programs in simple programming languages. In school I was walked through "Hello, world" in BASIC and found it interesting. There's something there in the quick feedback between coding and running the code that will either trip something in the kid's mind where he is interested in this or he isn't. I say start with BASIC, Pascal, or Java, something relatively easy. Start with simple, pre-done programs that offer a quick reward for the beginning programmer. If it sticks to the point where the kid starts reading and experimenting on his own, then great. If not, hopefully the father will be open enough to explore other possible interests with his child.
I would be worried that the father would try and throw the kid into the deep-end of the pool right away, in which case the kid is going to develop an aversion to programming. Start simple with some basic flow-charting and some basic programs. Maybe get some electronics kits to see if hardware appeals more than software.
One note. As the youngest of three sons, I programmed on my own and in conjunction with a few friends. Generally speaking, until the news media starting hyping programming as a great career opportunity none of our parents seemed particularly interested in what we were doing so long as our grades were decent and we weren't getting in to trouble. Whether its programming, playing basketball, or anything else, so long as the father takes the time to participate in the activity with his child and encourage the child to pursue his interests (other than pro-gamer), I think good will come of it.
Real Users find the one combination of bizarre input values that shuts down the system for days.