[dasmoth]

Are you confusing wing span with body length?

In the right hand panel of the video, the insect certainly moves several body lengths, and is still moving downwards at the end of the clip.

[Kiro]

No, it says "20 body lengths downward, and then [...] gets up and “walks” to the side, then steps off into the air". In other words 20 body lengths while being in the raindrop, which doesn't happen in the video. In fact, the raindrop barely touches it.