Tyree play should not have counted

While reading the article in Sports Illustrated about the Tyree play, I noticed that in picture sequence there was something fishy. I have highlighted the problem areas.
There were possibly two blocks in the back on the same play.
The first picture there is not too much contact. It seems from the video that he just brushed the back of the other player.This is a screen-shot of the YouTube video. It happened right before the second image above. The lineman apparently followed through with his block in the back.

Examining footage of the play:

For the second picture pause the first video below at 17 seconds in or just watch the movement of the lineman #67 Kareem McKenzie.

Who, me?

You see that it is an obvious block in the back.


Different view pause at 10 seconds in.


Don't get me wrong, penalties go unnoticed on every play but I had to put this one out there.