Thank you for your kind patience, Professor.

After reading the feedback on this thread and rewatching the videos, I realized that my mistake was in the concept of "shatters". From minute 51:20 of lecture 5, we can say that "a data set of size k can be shattered by script H (the hypothesis set) if there exists a choice of points in the data set for which all

dichotomies are possible".

I realize now the 3 colinear points don't imply that a data set of size 3 can't be shattered by 2-d perceptrons because there are other choices of 3 points for which all dichotomies are possible.

Slowly the fog is begining to clear...