On the back stretch (I think) he or she is running a very low line that is causing him or her to have to turn almost 90 degrees into the next turn loosing lots of momentum. Not saying this is all but it’s the first thing that jumps out.
Tough to say 100% without being able to stand back seeing a bigger view, but looks like a 4 wheel drift and 2 of the turns it's worse, as pointed out running that low line boxing it off is not helping but is not all the issue.
Did the driver give any input as to a certain thing ?
He said his arms were tired from having to hold the wheel to the left. Thinking he is really tight then it snaps loose in the center off. I did talk to him about his racing line and not to turn so sharp in the corner to keep the momentum. Going to loosen it up for the next race.
If you determine it is more 4 wheel drift If tires are lacking to much bite could cause it, If you feel tires are close two most go to fixes would be Raise Vertical Center of Gravity, lower left side percentage.
It looks like the tires aren't biting enough. Also looks like too much air pressure, when he hits the bottom of the track it beats him to death and bounces up the track. Just my opinion, I've never ran treads. Post up tire brand, age of tire, wheel width, and air pressure.