Everything said above, and remembering from when I did mine with an inspector in 2008...
Can a student fly in Class B? What about at LAX? (There are a list of Class B's in the FARs where it's not allowed, and LAX is one.)
If somebody has one eye and one leg, can they get a medical and pilot certificate? (Led to a discussion on SODAs)
If someone has their own plane based 15 miles away, can they fly it to your airport for training once they are solo?
What are the different types of hypoxia...? (I wasn't up on that subject, and as it was 4.5 hours in he called it quits and told me to revise Hypoxia. So I later passed with a DPE a few days after.)
In all that 4.5 hours, I wasn't asked ONE, SINGLE question about airplanes, aerodynamics, teaching/learning. This was at a time when the FAA were making all initial practicals be assessed by Inspectors, and I had it on pretty good authority that they were frequently failing people after half a day as they could still claim a full day's wage and get out of the office, then head off to the golf course in the afternoon. Essentially nobody was passing initials, and they would just find something obscure and hit you with it until you disappeared up your own asshole trying to find things in the reg's that you'd never come across.