I just did some tests with this and yeah, it works, but why does this happen?
I built a 50 block tall pillar and took no damage. I even decided to remove the entire center of the pillar aside from two blocks at the bottom and one at the top. Lined myself up and fell off the side. The two blocks saved me (one block does not work).
OP I'm guessing what happens is sometimes you fall but land next two stacked blocks and get lucky.
Not really sure how to feel about this.