Possible Issue - Fallout Tutorial Video

Hello, 

I’m working through the Adobe Analytics Workspace certification training and noticed what may be an issue in one of the Fallout tutorial videos. The same wording appears in the video and in the transcript, so I wanted to check whether I’m interpreting it correctly or if the tutorial may need an update.

“The blue portion of the bar shows the percentage of visitors who fell through and performed the next action, whereas the gray section of the bar shows the percentage of the visitors who did not. And this is all against the total of visitors who arrived at the first touchpoint.”

My understanding is that the gray portion is against the previous step. That is what works out mathematically. 

Can someone confirm whether this is an error in the tutorial, or if I’m missing something in how Fallout is being explained?

Thanks.