I'm not sure that kind of thing is much of a screw-up, the interface needs work, that's for sure, but there are a lot of websites that require you putting your mouse anywhere on the screen that figure out what to do. Maybe some spelling out is needed, have an arrow pointing down next to the season/episode number, but there are a lot of websites that work like that, CN just happened to not choose a better one than that and it can cause some users problems.
I know the facts are there, what annoys me is that he keeps giving them in a passive "faux enthusiastic" tone all throughout the video and unnecessarily keeps his sarcasm until the end rather than just going ahead and plainly stating them. I know he's not trying to sound annoying to any viewer and that he intends to point out the flaws, but if it's his way to avoid looking like any basic CN hater, he's doing too much. Maybe it's just me, but I felt like he overdid it