Just came to show further support for you Green
Its simple, either the ex wsnts to contribute and hold good to his commitment to the deposit, or he doesn't. The abuse is clear when he starts to threaten that his committed to contribution could actually be withdrawn if other criteria of his design are not met.
He has no right to do this. He either wants to help his ds or he doesnt.
I would set away from him, your poor ds and yourself have once again been caught in his trap financial coercion trap believing he would be good to his word, so have planned have budgeted accordingly, but, at this late hour to threaten its withdrawal is just blackmail and coercion.
Nobody elae has to understand this, I'm sure your WA liaison will understand this completely amd advise you the same, that money and presents given belong to the receiver and are given freely and without condition, as is love.
Sadly, he has taught you yet another horrid, but yet valuable lesson.
He has really driven the nail home that his contributions will always have conditions, and are not freely given, but used to control.
It is not possible make plans around abusers as your exact situation is the outcome.
Refuse his money, ask for help from the uni or other sources and explain the situation.
Ask him to either let his ds have the promised money, or not, but just to confirm one way or the other, no other info needed just an 'are you withdrawing funding or not, where the remainder comes from is unrelated and doesnt require your input'.
Ignore any pp who just want to have a dig at you or crticise.
The upshot of your ex potentially withdrawing his conditional offer of funding might mean that yiur ds will have to use his hard earned savings to pay for his deposit in full and lose his holiday.
That will be a result of his fathers coercive financial control. Nothing else. Very sad.
Can he go away with a few hundred less to spend? Maybe share it across some credit cards, or find a zero % interest deal?
You will all know never to trust his words again. Hopefully this will be a trust fully broken and never trusted again. Dont listen to him ever again, if he hands over money, fine, but talk of it is just control over you clearly.