I'm not an expert by any stretch of the imagination---however.

Girdling is the ancient practice of removing the life sustaining bark all the way around the tree trunk and letting it die and dry standing before felling for use in log cabin building.

The question is how much was removed as a percentage of the diameter?
Is 5 inches of width 1/2 of the bark as measured around the tree?
If so that's a lot.
I have seen trees that survived something just like that and only the limbs above the missing bark died off.

BTW, once they are large enough, I harvest the young Maple trees that pop up in Grammys back yard and make really nice walking sticks out of them.

I also collected and brought home a few hundred seeds to start at the edges of my own back yard.

It would have to be less than half of the perimeter of the tree. Maybe even under a third of the bark around. The tree is about 7 or so inches diameter I think. So if its 21 inches around and five off, only about 25% of the bark was removed, excluding the vertical lenght of the tear. All of this is without exact measurements though.

So far its holding up well... but often times its a slow decent to death for trees. I'm still hoping it will make it. It was just getting big enough to give us some shade...