I found a split in one of mine yesterday and never would have found it with just doing the bend test. It was a very small split ( about 1/2 inch ) and it took twisting to find it. It opened up just barely enough to see it was split. I could probably have shot it a few more times before it got really bad but why take the chance. I am new to archery and didn't even know about the test when I first started shooting. i was lucky I didn't have an accident after all the times I hit arrows before I moved off the 10 yard line. I was shooting at a Block and I know there are different places you can shoot on the Block but I always choose the middle to lessen the chances I might miss the target and loose an arrow. At this time when the arrows hit I just visually looked at them - then I saw a couple pictures of arrows through the hand and I read about the bend and twist test. Now I check each arror before I start shooting and after shooting them several times after that - and everytime they hit close. If I had seen the arrow through the hand before I bought my first bow a few months ago - I would probalby have not bought it and simply bought another rifle.
Once I seen the pick of the carbon arrow through the hand I check them now myself, bend and twist. Also if you get "tuned in" its not smart to bang arrows into one another. Maybe thats obvious, but I've seen people do it. I just get a taget with some spots and/or move back.
October 2011 FYI, Graphic pic. http://www.huntingnetwork.com/publisher/Hunting-News/2011/10/17/Michigan-Bowhunter-Learns-Lesson--Inspect-Your-Carbon-Arrows