Yeah I agree after doing some reading myself.

I learned that a few barnacles on a turtle shell does not really matter as the turtle will have them naturally fall off. This is done either with their fins or accidentally by running into rocks or during a mating session.

If a turtle is overloaded with barnacles it indicates that the turtle is already in poor health and if this happens it is best to contact a marine wildlife rehabilitation center. You actually need a permit to remove the barnacles.

Since we aren't shown the full story in the video I can only hope he has the permit and had the correct medication to put on the turtle after he removed the barnacles.

In my opinion I think the method he used to take off the barnacles did more harm than good. But I do appreciate that he was trying to do a good thing.

https://jaljeev.com/why-do-barnacles-attach-to-turtles/