My criticism about Lukas isn't centered around team values.
As a talented youngster, I was always inundated with demands from coaches and teammates to make increasing sacrifices and tame my lifestyle to serve them. They insisted that being talented meant I was indebted to them, the untalented. I found that the same drive that made me study late into the night was that same unwavering drive with which I broke my equally talented, increasingly sacrificing competitors on the track. The key point here is that I came in from the outset with a take it or leave it offering of my abilities (I was recruited off the soccer team after breaking our school 3200 record in the preseason 'fitness test'. 9:46 if you're curious).
Lukas signed a letter of intent, accepted a scholarship, and committed to competing for the University of Oregon. There are reasonable ways to breach this commitment. His defenders must answer the question: what is the threshold at which his desertion becomes unreasonable? In the middle of a race? Right before nationals? Immediately after a poor showing?
He deliberately acted in a way to justify certain expectations of him and then pulled a 180 and punished those who thought he was an honest actor when he established those expectations.
Lukas owed his team advance notice, especially since by recruiting him, Oregon sacrificed recruiting several other talented runners. He screwed over not only his team by betraying the expectations he created, but he spit in the face of every kid who he beat to get that spot.