Not anymore. In the olden times you needed a crossover cable to connect a PC to a router without a switch (or a switch to switch, router to router, etc). Now with Auto MDIX (medium-dependent interface crossover) modern devices can determine whether the connection needs to be crossed over. Modern is very relative term though, it's been available for a long time.
I don't recall if I left it out because I covered it elsewhere in my class or forgot to do it when I made the video. Next time I teach the class I'll review the video and possibly update it.
