Not sure that's due to it being a bad broadhead. You make a two inch gash in both lungs and that deer should be dead in 7 seconds. Sometimes that just happens, even with firearms. I shot a little six point broadside with a 12 ga slug taking out the back side shoulder. The deer ran past me on three legs and kept running. Followed good blood for 300 yards and even found a piece of a rib in the blood. Never found this deer, but I believe he was stolen. Bottom line is that the deer should have fallen in sight, but didn't. It just happens sometimes in my experience, even with perfectly performing weapons.