Things were going well. I had cut the biscuit slots on two sides and marked the third piece of oak for slot cutting. At that point I left the work and went to another part of the shop to see what one of the other students was doing. When I came back, I looked at the piece of oak, and somehow got it oriented backwards. I didn't check the orientation, because I thought I knew what I was doing. I cut the biscuit slots, inserted biscuits and checked the fit of the oak band. Of course, it was backwards, so the miters wouldn't fit. I only had enough material for the four sides of the table top and so was now faced with a problem. I thought perhaps I could re-cut the slots on the reverse side of the oak strip. That worked, and I continued with the fourth side.
I glued up the three sides that had been cut properly, but just couldn't bring myself to glue on the fourth piece with slots on both sides of the strips. It looked funny with slots showing, so I quit for the evening. It was time to clean up anyway. I'll have to buy another piece of red oak and make a new strip at my next class.
Lesson learned: check things more than once.