Reducing PIP points?

I am starting to wonder if the reason for reassessing previously awarded PIP is to reduce the points. My son who is autistic was originally awarded 21 points for the DLC of PIP. Last award he lost 4 points for Communication of all things! but was still awarded enhanced rate as he had 17 points. His new award came through this week and he has lost another 4 points, now down to 13 points. The decision maker said she had amended his replies on the form to fit her narrative (paraphrasing). I am concerned that the whole point of keep reassessing is to reduce his points down to standard rate and perhaps ultimately, to stop his award altogether.

Although he still qualifies for DLC I am wondering if we should put in for a reconsideration? I did put in for MR when he lost points last time for Communication but it made no difference. What should we do?

Many thanks
Melrose