Read the story and looked at the pics. Do you think that may have just been a severe enough angle that he missed??? Almost looks like a slice on the side of the deer not like it went into the deer and back out after hitting a rib. he even suggests that in the story when he says, "I had a more quatering away then i wanted at 5-7 yards. I thought was a perfect shot turned out not to be. I was shooting 2 blade rage. One of two things happened, the arrow deflected off the rib or i just slightly pulled the shot." Almost looks like a pulled shot that just went through the outer profile of the deer on the hard quarteeing away shot. JMO
I recall a buddy of mine shot a buck 2 years ago, at probably 3 or 4 yards, quartering away a little and did the same thing though too. Deflected off of the ribs, but his went the other way and went in and through the deer. Didn't bleed much and it was a long tracking job of a couple of hundred yards, but we found him. That was with a fixed blade of some kind.