backwords counting.

My nephew always says times backwards, like descending order. You ask what time he woke up or got home from school or whatever and he'll say 8 or 7, instead of 7 or 8. And if you say to him that a thing happens at quarter to 10/ half past/ progressing times instead of decreasing times, he never quite understood what that means. Counting also, he would say he has 6 or 5 sweaters instead of 5 or 6. He has ADHD and yesterday someone mentioned bipolar might be a thing to ask about in therapy, but we know that at 14 he is too young to be diagnosed for that anyway. Is there a reason for descending count thing?