It has been observed by one of our forum members that given how far the free knee has already advanced ahead of the vertical plane, Carmelita’s grounded ankle should already be extended. This may account for her relatively slow time. But our coach also notes she was probably tired coming into the meet after international travel from the US westcoast.
Of course there may be other issues. This is an image of a very brief moment frozen in time. She may have hit a soft patch in the track (if it was suspended on boards for example) which may have rocked her back onto her heel.