When a series of unconditional chain command blocks is run that clones another row of unconditional chain command blocks onto itself it runs that cloned row as well even if they aren't facing the right direction. 

Video: https://youtu.be/SQihXdWBk0c

It was really hard to demonstrate this so I did my best using some say commands. All command blocks are labeled by their row number(from 1 to 5 from front to back) and their block number(from right to left inside chains).