Not sure? Read this article wrote:
Anon wrote:http://www.sltrib.com/home/4073165-155/track-and-field-former-byu-star
"They said I cut in (on Engels)," Walker said.
"From the angle they saw, we're like, 'OK, that's cutting.'
But if you [totally ignore that and] see it from a side angle,
I came in to pass the guy in front of me … he (Engels) just ran into me."
Good grief. It doesn't matter why he came in.
The point is that he cut in on Engels, and caused the collision.
I don't know either of them and would just as soon see Walker do well,
but unfortunately he's the one who did the cutting, and that's why he is DQ'd.
It absolutely matters that Walker changed his direction in the straight because of the runner in front of him and the pertinent USATF rule expressly says so.
Rule 163.3:
"Each competitor shall run in a direct line after entering the final straightaway in all races of two or more turns unless there is another competitor in his or her path."
That is a critical "unless." Most interference claims in the final straight involve runners who are leading (or have a clear path). Walker is allowed to change his path to react to the runner in front of him and he's not supposed to have eyes in the back of his head.
If you put yourself in a position where you are "third in line" as Engels did, you can't just complain that "second in line" weaved. He's allowed to weave.
Terrible call. All the more so because neither of them was likely going to qualify and Engels put himself in a position where he was trailing a runner who wasn't going to qualify.