It is not reliable to use the animals reaction to the shot as the basis for a hit. I have seen well hit animals react many different ways. Blood trail is the best benchmark that the critter is wounded. Some examples:
1.) Gemsbok at 202y shot with 308 using 180g bonded. At the shot the animal ran away with no visible reaction, no kugleschlag, nothing. PH exclaims, you missed him. I knew my shot was good but we saw what we saw. PH went of to track the beast. I walked up to where it had been standing. PH returned to say it was a clean miss. I took him to the spot where I had found only 2 drops of blood. Clearly wounded. Despite my being unable to find more blood the trackers found it dead only 60y from where it was shot.
2.) Bushbuck in the dark while night hunting. The animal was moving and upon the shot the PH declared that he heard the impact. I was not as sure of the shot since I could only see the eyes at 180y. I thought he had said it was a Duiker and so, I held 6" behind and 4" below the eyes. That turned out to be over the back of the Bushbuck. We searched in the dark for 1.5hrs and the next morning for 2hrs finding no blood or spoor PH declared it a clean miss.
3.) TN wild boar hunt with dogs with 308. Shot with 165g Nosler BT at 5ft perfect broadside shot on boar that passed thru the boiler room and out the other side. I was so close, I could see the entry wound but the boar did not flinch and ran away but dropped stone dead after 30y.
4.) The biggest, best white tail deer I had ever seen. Shooting at 30y with Winchester 94 trapper in 44mag. Fired three shots at the deer with zero reaction. It did not flinch or jump or run away and I was so close I could hit it with a rock. Had a red dot on the rifle that had gotten knocked off alignment and all shots were 8-12" high after testing. The deer just walked away with no hits. We dubbed it the Ghost Buck. That was the only deer I had ever missed.
5.) Mauser 270 on whitetail at about 80y. Buck ran down mtn to me as I was leaving my tree stand. I was out in the open field walking. Deer ran out and stopped. I was surprised at best and took a quick standing off hand frontal shot which hit high and left in shoulder grazing rib cage with 130g BT that did massive damage but deer did not react but ran right toward me. I fired three more shots as it ran past but saw no signs of impact. Found blood trail which was massive and then tracked the deer for 2hrs and about 400y before finding it dead after dark.
6.) Whitetail buck at 60-70y shot broadside with 375HH 250g TBBC. At shot deer ran about 30y and stopped to look back. On 2nd shot deer dropped in its tracks stone dead. Neither round showed any signs of expansion and was total pass thru.
Must find blood to declare a wounded animal. Lunch shots will take a while to bleed but some blood, hair, tissue should be found just behind point of impact. My 2 cents.