DLA stopped , was it unlawful? reclaim lost money?

I am in process of reviewing DLA being stopped in December 2016 due to move to PIP for my mother. Her conditions worsened in 2017 had many falls an hospital visits, the time to return the forms expired an lost the ability to continue onto PIP from DLA.
Now I read these stories an just wonder if any room to claim lost monies? Especially in light of recent court hearing outcomes for other claimants.
www.benefitsandwork.co.uk/news/3861-15-january-2019-update
www.benefitsandwork.co.uk/news/4154-192-...m-unlawfully-stopped

Yes thank you for your answer, an as she cannot do any of this on her own an as I just had new born 2 months prior it lapsed!, im now in process of submitting a new pip claim. Interestingly a recent phone discussion with PIP claims line about the pip 2 form when i raised the query about backpay (my understanding can only go back upto 1 month or to date of the requesting the first form or on date they recieve the form request) their response implied to put details on the form for it to be considered was as if they may consider going further back than that? any thoughts on that!? also I could not see anything in the manual about this we have plenty of evidence of her disabilities.