Ridiculous!
There's a point where footy no longer exists because the very act of playing footy may result in the culmination of actions, inactions and circumstances, intentional or random, where someone potentially may have a concussion injury.
Chol did nothing wrong, unexpected or that could reasonably be forseen would cause Stewart's head to hit the ground.
If Chol should not have tackled, equally Stewart should not have tried to run through traffic as fast as his legs could drive him while bent forward on a 60+ degree angle.