This is how athletes get to be insufferable prima donnas...because fans like you forgive every transgression after they do something impressive at a young age.
By the time Mary gave this interview, she was an adult and a full 8 years had passed since the interview. She made no attempt to show any class.
If you trip on someone in front of you it is your fault. If she was clearly the superior runner, why not pass wide with a huge acceleration? There is no risk of tripping then.
The only conclusion I can draw after watching Mary's tactic is that she did not have full confidence in her speed or fitness, so chose a risky move. This makes me think she was not the best runner anyway.
Anyway, condoning childish behavior in adults, based on something they did when they were 14, is preposterous IMO.