With today's modern archery equipment I don't believe a "marginal shot" exists when talking about bone. No reason you shouldn't be able to reach vitals after hitting any bone except maybe the spine on the front half of a deer if your equipment is up to the task. In this case you blamed the broadhead and yourself for the marginal shot. In my opinion the blame lays 100% on the broadhead. A sturdy fixed blade head like the slick trick you're shooting now would have undoubtedly held together and reached vitals. That's why I don't shoot rages. If one of my target bucks is standing in front of me quartering to while I am at full draw; I'm not going to stand there wishing he would turn broadside so my broadhead can perform. I'm burying my pin on his collar bone and sending that arrow on its way with 100% confidence it's going to slam home and reach vitals. If his vitals are behind the paddle due to the shot angle, we're gonna hear it crack because I'm 100% confident that BH will make it.
Years ago I shot a smaller buck quartering away. The arrow went in behind the last rib, through vitals, busted the paddle bone and was laying on the ground where him jumping flipped it out the exit. Some guys have trouble with paddle bones on entrance. That slick trick managed to bust through on exit.
I also have another bone where a ST busted through the leg bone below the paddle maybe an inch below that big ball joint on exit and still passed through.
I shoot trick because I've seen them perform past my expectations on a rough hit. And the hole they leave is crazy compared to the size of the head.