He just got the race wrong and realised it on the turn.
Could be wrong but I do think I remember hearing that Kerley's injury - probably the same one he had last year, if I had to guess - had something to do with his ankle (?) and inhibited his ability to run turns well as a result ... but I guess running straights is fine for him. I guess that helps narrow down his place on the relay lol
Yes, I think I read in the WaPo that was the main reason he switched from 400 to 100. Ankle was swollen after running the turns. Not sure that's the issue here though.
World Athletics feed says Knighton's 19.77 from today is a world U20 record, but they also acknowledged his 19.49 earlier in the year. What gives? Why wouldn't his 19.49 count?