This happened to me just last weekend. I had a buck come in and offer me a slightly quartering to shot. I put the pin on his shoulder and watched the arrow hit the mark. I waited almost an hour before getting down and going to look for sign and the arrow. Well low and behold I had guts on the arrow.

I backed out quietly, went for breakfast, went home did some Christmas decorating and went back about 4 hours later. I was sure I had the lungs hit but the guts made me second guess myself. I went back and found the deer within 60 yards of where I hit him. It turned out he was quartering more than I thought and I ended up catching both lungs and out through the stomach area for a complete pass through. (basically hit a little of everything)

The good news is I didn't push him and he died quickly and in a short distance. You did the right thing.....let us know how it turns out.