mummy Sorry this is long, I hope you read it because I hope to explain some of it :)
I work with, and have worked in the past with, a number of vulnerable families some of whom have/have had CP involvement.
Without exception, in cases like yours, parents feel that:
The SW is "shit" or has got it in for them
The SW wants to take their children
The SW is seeing things that aren't there
They don't need any support
The other professionals have also got it in for them...
If you agree to something after court is threatened, that is seen as not being obstructive, but is not positive because you're agreeing to avoid a 'sanction' and not working with the people who are working to make sure your children are safe because you understand why it is necessary.
As far as the MH assessment goes, they are only commenting on your partner and his current mental health status. The SW are acting on behalf of your children and they are assessing the risk of harm to your children should he have another episode in the future. As someone else said, it is conjecture, but looking at history, patterns of behaviour and other contributing factors is the best tool the SWs have for assessing the risk of future harm. And your reaction to it all demonstrates your ability to recognise the potential for that risk to arise and your ability to respond appropriately to it if it should.
For example:
An Initial Assessment was completed on my family a couple of years ago. My exh and I discovered that a PPRC had had contact with my children over an extended period of time. There was no risk from my exH or I directly, but they had to assess mine and exH's ability to safeguard the children from any risk. We already had suspicions and so had been safeguarding them (never alone with the person) and the case was closed.
It is horrible having someone come into your home, and comment on your decor and furnishing in a report along with questioning how you discipline your children, and what activities they do before corroborating it with your children in their bedrooms in private (so that they can see the state of their rooms, whether they have a bed or not, the presence of age appropriate toys etc). But you do it.
The Police were also involved briefly. They had no concerns whatsoever, but that's because they were interested in whether a new crime had been committed. But the LA still completed their assessment because they were interested in mine and exH's ability to protect our children from this person. Even though the Police were not interested (no reason to be) the SW told us that if we continued to have contact with the person/people involved then they would progress to a S47 Enquiry. Even though a crime had not been committed. It was a done deal because ExH and I had already decided we wouldn't have any contact with them again, but can you see the parallels between this situation and yours?
In your case, the MH team are my police - there is no reason for them to be involved, but the SWs have a different agenda. The LA need to believe that the parent/s have the ability to recognise risk and protect the children from it should it arise in the future.