Looks like some inaccurate assumptions to me.
First, where's the small washer that goes behind the head? It looks like it's missing, and that's why they blade folded back into the arrow. Kinda like forgetting the tip on a muzzy, and then wondering why the blades fell out. <img src=icon_smile_wink.gif border=0 align=middle> And calling it a failure.
Second, the blades will always fold back in when the arrow stops. When I pull an arrow out, or find it on the ground behind the deer, they always look like the two blades above, and if I remember to put the head on correctly, all three look like that. <img src=icon_smile_wink.gif border=0 align=middle>
I may be looking at this wrong, and missing something, but I just don't see the washer, and I don't see how anyone could expect the blades to stay open once the arrow stops, a simple branch hitting the fletchings as the deer runs will pull it back a little and the blades will fold back in. I'd tell your friend to remember the washer, as it would get epensive replacingg every single arrow shot with an expandable, be it a miss, pass through, practice, ect. I wonder if your friend ever practiced with the broadhead, you would think he would have realized how to put it together correctly after ruining one of his practice arrows???
One other thing, even with just the one blade, if he hit within an inch of where most of us aim, the deer still would have dies within a short dash. One blade through the top of the heart and both lungs still kills rather quickly, I'd imaginee. I wonder where he was aiming??
Another "mechanical failure"? Sounds like "archer failure".
"In heaven, even the fish have antlers"