Mixed age couple and sdp (again)

I have just had a couple referred to me.  He has just turned 65, she is 58.  They were getting ib-ESA, the claim was in his name.  She gets hr care DLA, he gets er PIP daily living.  She claimed CA for him, but he didn’t claim for her so they had one sdp for her on their ESA.
HIs ESA stopped at 65 and they were told to claim UC, which they have done and it has resulted in a huge drop in income.
They shouldn’t have been able to claim UC because of her sdp - but what should they have claimed?  He can’t claim PC because they’re mixed age, and she cannot make a new claim for ib-ESA. 
Is their only option to continue with UC and ask for the compensation payment?

In this situation I think the older partner is treated as not having reached pension age and is entitled to continue to receive ESA .

See paras 11 to 14 https://www.gov.uk/government/publications/housing-benefit-adjudication-circulars-2019/a92019-mixed-age-couples-further-guidance

If that is correct theESA should not have been stopped and they should not have been allowed to claim UC.

Brilliant - thanks for this Ian

Now to get them through the repatriation process :)

Who told them to claim UC may I ask?

Jobcentre Plus - they ended his ESA claim and told him he had to claim UC.

In that case, I’d definitely be looking to also make a claim for Financial redress for maladministration

The whole mixed age couple change has been pretty bad anyway, you might expect the government department responsible for administering the change to at least know the exceptions.