First of all, "thanks" to everyone who responded to the post below; your input was valuable and it looks as though there is overwhelming support to let the grade stand. I also counseled with some fellow instructors and my department chair who all echoed your sentiments, so even though I haven't contacted the student with my decision yet, I do believe I will leave the grade alone and allow him to suffer the consequences.
But back to the running...
As per this post's title, it is currently 4:14 am, ugh. I am planning my 20 miler this morning and I want to get it done first thing, so I plan on leaving home here around 5 (currently, I'm trying to wake up a little -- eating some cereal for pre-run fuel and drinking a cup of coffee to help with the "waking up"). So, why am I doing the 20 today and not this weekend? I had to bump it up in the schedule because we leave for our trip to MN tomorrow, and it will probably take us 2 1/2 or 3 days to get there (we're driving -- taking the Scooter dog with us, who is doing much better, thanks for the concern on his part) and so I won't have an opportunity to accomplish the long run this weekend -- and trust me, I'm not relishing the 3 days in the car after 20, I suspect I will be very sore.
I will fill you guys in later today on how it went; cross your fingers for me -- it's a long way to go!
*6 am edit: The 20 did not "go." I will explain later -- right now, I feel like crawling back into bed, pulling the covers over my head, and re-emerging sometime in the second week of January (after this marathon has passed).*