!2 year old mechanics

My son is 12 years and 10 months. 5ā€™1" 100 lbs. Throws 69-73 fastball. Please provide feedback on his mechanics.

Difficult to see his mechanics in detail due to how far away the camera is.
One thing that jumps out to me is that he looks like he finishes too upright with an abbreviated follow thru. His stride looks a little short to me, but it looks like he does brace up with his front leg well. Again, tough to tell.

Compare re finishing position:

Or the 13uā€™s follow thru position from this thread [