Article is nonsense with relation to science. Snapping the lead leg down too quickly if even at all possible and I am not sure it is, would probably create excessive rotational forces at the ankle and a longer contact time in the next few steps. The idea of snapping the leg down is too prevent the problem of a collapsing COM on ground contact over the hurdle with hurdlers who are slow at getting their legs down and look like ballerinas instead of hurdlers. I am not against the snapping cue, but I would not use it for the purpose the article supposes is the key faster hurdling when every picture shown by shows it is the stepping through with the trail leg as the ending characteristic in elite hurdling.
I look at hurdle progression as a 4 step process, attacking, striding, snapping, and stepping. It’s not linear, but you can’t do 4th step in the process without doing the 3rd, and the 3rd with out doing the 2nd, and the 2nd without doing the 1st and if you are not doing the 1st you are likely walking or literally jumping over the hurdles. One can say that stepping through with the trail leg will cause the lead leg to come down and this is true, but it doesn’t stop the ballerina action. Sometimes everything comes naturally when the athlete starts attacking the hurdle, but sometimes there is a block in the process like with girl athletes who dance tend to want to be graceful and artistic over the hurdles. The important part is knowing when to cue which step in the process and how to set it up for the athlete to succeed. You can’t cue striding out at take off when the athlete is too close to the hurdle and you can’t cue step over when the athlete wants to be graceful instead of fast and powerful.