I am using Illustrator CC 2018, trying to do the same explained in this tutorial.
In the step 3, I don't see the intersection label between the circle and the segment (but they do intersect, I don't know why).
That prevents me from deleting the inner part of the rect segment.
In any case, is there any quicker way to do this? I have like 100 wire intersections and going one by one can take a long time.