Need help understanding my 7 year old 7 month and 24 day old sons score from a recent OT evaluation. Here are the subtest scores:

DTVP-2
Subtest-Standard Score, percentile

eye hand Coordination-11 (average); 63percentile
Position in Space- 12 ; (average) 75 percentile
Copying- 13; 84 percentile (high average)
Figure Ground- 7; 16 percentile (low average)
Spatial Relations- 11; 63 percentile (average)
Visual closure- 13; 84 percentile (high average)
Visual-Motor Speed- 14; 91 percentile (superior)
Form Constancy -14; 91 percentile (superior)

Composite Scores:

General Visual Perception- 113-81st percentile
Motor Reduced Visual Perception- 70-2nd percentile
Visual Motor Integration- 85; 16th percentile

My question is, my son scored average-superior in all subtets on this test except for figure ground where he scored in the 16th percentile and low average. How is it possible that his motor reduced visual perception composite score is only in the 2nd percentile and his VMI score is in 16th percentile. The General visual perception score makes sense but these other two do not make any sense whatsoever. Did the OT make a mistake in her scoring? When I asked her, she became somewhat offended and said that studies have shown that composite scores are not valid and you need to look at only the subtest scores. She stated that his only low average score was in figure ground (7) and he does not need OT. Again I am very confused concerning the composite score relative to the subtest scores which were overall quite high. Can some OT out there please respond. I should also note that when I compared his scores with someone of his own age on this site his composite scores were much higher even though my son had scored almost all higher with the exception of the figure ground score. This was a private OT that I had him evaluated by. Thanks for any input.