I am a recovering alcoholic as most of you know. If I had not been sober as long as I had when my oldest grandchild was born, 12 years ago, there is no way in he!! my daughter would have let me near her yet alone take care of her.
My daughter is extremely 'picky' on who the kids are left with. There are only two of us, beside her on the list at the schools that can pick them up, and we have to show identification.
I understand that your RAH probably thought he was doing a 'good' thing, however, A or not, most men do not have the concerns that a mom does. His thinking went probably something like ........................... oh she's been taking care of her grandchild, great she can take care of our kids, she has recent experience. Totally NOT thinking about the age of your children, the fact that there are 3 of them, and that one has special needs.
So poor baby (said with dripping sarcasm) got his feelings hurt. Too bad. You are doing what needs to be done to keep your children safe and protected. In your shoes I would have done exactly the same thing.
And were you to eventually 'interview' her, it would not be a 'no-no' to ask her how long she has been in continuous recovery, and does she have any experience with a 'special needs' child, and does she have any limitations that would prevent her from chasing after 3 very youngs ones all at the same time, lol etc
So maybe you can tell him you appreciate his effort (if you do) and let it go at that.
I see nothing wrong in your saying NO.
J M H O
Love and hugs,