[kens]

I know I shouldn't even get involved here, but I looked at day 8 vs day 9 very carefully and day 9 clearly builds on day 8 (e.g. the disableSelection code is carried over). The indentation that bothers you is feature testing code cut-and-paste from http://api.jquery.com/jQuery.cssHooks/. The additional JS code for the ball animation is totally reasonable for someone to learn and implement in a short time.

TL;DR: there's no red flag here.

[ars_technician]

TL;DR; people make whatever justifications they want from the code to support their stance.