Right to return of Holding Deposit

[Tyzz]

DS paid a holding deposit on a rental.
There was a lot of work needed doing but he was assured it would all be brought up to scratch.
I went with him for a second viewing and it's shocking.
What it needs is a full renovation.
The house is in a filthy condition and poor state of repair. This is apparent even though some of it has been painted. The decorating seems to have been done with no thought of even cleaning first.
The decorator was painting around some filthy ancient curtains and had painted some cupboards shut.
There is damp and extensive black mould inside cupboards and around windows, some kitchen cupboards are black with mould inside. The estate agent said "we'll get them painted".
There was rubble in cupboards, a broken electric shower, and much more.

It's not cheap either. However DS paid nearly £200 as a "holding deposit". He's not going ahead with the tenancy but does he have a case for getting that back?

Did he pay the holding deposit before the first viewing? Was he given any terms/conditions? Where did he pay the deposit, over the phone or in the LA office?

He paid it after the first viewing, paid online.

Admittedly he was naive to not have realised the extent of repairs needed and he didn't do as I did and open every cupboard and drawer. However he was reassured by the EA saying it would all be put right and in fact the landlord is obviously not interested in doing anything other than a superficial paint job.

Does he have details in writing of what the letting agent says the landlord would be putting right? Has the landlord finished the work?

It really depends on what the paperwork/terms and conditions say but as he paid after seeing the place, and the landlord is doing works, it might be tough to argue for his deposit to be returned unless the landlord is refusing to do something which he is legally required to do like a safety cert, or that its been agreed in writing he would do something and now he's not going to do it.

I don't think he has the promised work in writing, I will ask.
The work isn't finished but it was obvious to me that it was a superficial job. The young man from the estate agent seemed surprised when he looked at some of the things I pointed out.
As to safety the boiler looked decrepit but there is a gas certificate from a few months ago. The gas certificate passed it but gave some recommendations which haven't been done.
I think the work agreed was fairly superficial ie replace flooring and decorating. Even if he had seen the mould I doubt DS would have known the significance and he would have believed that painting over it would solve it.

DS hasn't done this before, it looks like it might be a costly lesson.
I think that if they paint over all the mould DS would have no way to prove it hadn't been properly fixed and there could be problems down the line. He is best walking away but I wondered whether he would have a case for getting the deposit back.