I don't believe the father's goal was that she learn how to use a can opener. I believe it was an attempt to teach her how to analyze a problem/challenge and work out a solution.

Yes, he could have demonstrated how to use the can opener. If he had done that, it would have bypassed the whole exercise of leading questions about how to look at something and discern how the parts work together to accomplish a purpose /desired outcome. Acquiring the ability to methodically examine something unfamiliar and then make it work for you is a useful skill. It potentially goes way beyond a can opener. There may come a day when she _really_ needs to figure something new out when nobody is there to show her (or to just do it for her).