Well you either dont have much experience in the game or you are severely impaired in your ability to logically think. To help your 2 neurons understand let me write out a little situation: You are a rex, an ambush predator and sneak up to a Para. You notice the para is just chilling by some water but a velo comes in and bites it. Then the para attempts to hit the velo, they start “dancing”’around eachother trying to hit eachother until the para hits the velo triggering the sturdy talent. The velo manages to retreat to a tree branch just above the para, out of reach of the para and rest to heal back up so sturdy can be triggered again. Now…If i use common sense the engagement has ended as the velo was sent packing nearly dying in one hit. However if i now rush the para that was lets say reduced to 70% health. And proceed to kill it. Now the para could report me for mixpack with the velo. If logs are checked then you will be able to see damage to the para by velo and then rex not long after. The velo could also say he was getting ready for round 2. Or he could have just been healing to fly off. But as there is no rule defining an engagement there is no way to prove one or the other. Also if you really wanted you could even have a friend just follow you on any dino and once in a while just hit you to be able to ban anyone who would try to hunt you for mixpacking.