I just saw the dog bite photos of the person who rolled the dog over in an alpha roll. I have been rolling my dog for tick inspection. Should I be doing this?

I just read the article on dog bites where the person sending in the picture got bite while putting a rescue GSD on their side. I have little expertise with dogs much less GSD's. I have a 15 month old GSD who is on the large size and very powerful. What teaching I do with him is what I am picking up at the local Schutzhund club. Ever since he was an 8 week old puppy we do "inspection" which means lay down and roll over at what time I look over his belly and groin area for ticks (we live in the country and when he is out of the house he has access to tall grass etc.). As he has grown older some times he will bite on my arm during this inspection process. He will hold my arm with light pressure until I tell him no bite at which time he will let go. I complete the inspection or it may be that the inspection is done around the time he grabs my arm and I stop the inspection when he lets go. I pat him as I give him his release word and we are done. My question is, maybe I should not be doing this Alpha Roll thing. This is the first time I have heard such and don't want to take a chance on getting bite for something maybe I should not be doing. What do you think?

David