How to un-reset the Consumption calculator?

I had a weird thing happen today. Like many others here, I reset the mileage calculator on the multifunction display each time I fill up with gas, and I record the numbers in a spreadsheet for comparison with the mileage calculated from gas purchases. Today I was stopped at a red light and noticed that there was some dust on the MFD. So I took a dust-free rag and wiped it off. Unfortunately when I wiped over the lower right corner of the display I accidentally reset the mileage calculator - the mileage counter went to zero. I was very frustrated by this, and switched to the energy panel (showing battery SOC), then back to the consumption screen - still zero. Since I was at a red light, I was able to take out my PDA and quickly record the average MPG and mileage so I could average the results next time I fill up. This had happened once before, so I will have to get better at changing the display to another screen before wiping it off in the future.

Here's the weird part: I was less than 1/10 of a mile from my destination, so I drove there and parked for a couple hours. When I returned to my car and started up again, the MPG and mileage counter were restored to the values they had before I had hit reset. Apparently something I did caused the MPG calculator and mileage counter to un-reset.

Has anyone else ever seen this? Is there a specific sequence of events (open the door twice while simultaneously depressing the brake, operating the windshield washer, and pressing the panic button on the keyfob ) that can undo the reset and restore the mileage calculator to its previous value? It seems I may have stumbled onto an "Easter egg" to do this, but don't know what it is.