not claiming any benefits but still incapicated

HI

i am helping a friend and neighbour atm. When aged 13 he sustained a severe head injury on a motorbike . He now has Epilepsy , which is now regularly monitored by GP and controlled by a shed load of meds. If he were to miss one dose , he would begin seizures again. he does have times of confusion and taken wrong doses and ended up in hospital. However , from a cognitive point of view it has left him with limited learning difficulties and memeory , understanding, cant read, write . just simple tasks are enough. He has lived all his life with his Mum , who always looked out for him . He comes from a strong work ethic family , and has always done manual work only. My husband gave him work for many years as some employers were reluctant to take him on . He is a grafter.
His Mum had a stroke young , and he remained living with her and became her carer in supervision role. He still worked.
His mum then ended up in hospital and a care home.
Many years before , him and his brother bought the council house, with her name on the deeds. he Paid his half of mortgage to his brother for years and years.
Mum died this year.
He has since found out the house has a LA charge on it for care home fees.
it then gets complicated, which is where I come in and he is now seeing a solicitor, and I am helping him .
In a nutshell, he has been stitched up by his brother and his wife. He is not on mortgage, never was, there has been a remortgage , he never knew about, the LPA ( wife) has mislead LA and basically denied anyne lived in the house. He paid all bills , all still in his mums name, but took their word the reason everything was in his mums name was because it was too much hassle to change.
In my view, he is vulnerable and has been financially used and abused. The solicitor agrees this appears to be the case. He does have a case for beneficial interest and that is the goal.
The question the solicitor wants to know :
Does his incapacity, brain injury and epilepsy, give rise to the level of incapacity to qualify for DLA/PIP/ICB/ESA ?
If he did , then the LA should never have put the charge on.
He now lives alone , he does the same thing everyday. gets up, goes to work, comes home.
he is unkempt and eats off the hoof , if you like.
Having looked at PIP and communication etc , there appears a strong entitlement. But would value your thoughts. TY in advance.