You did the right thing , like other pp I would rather have a screaming parent at me than risk a childs safety.
My DP would say the same as your dh but would still do it ( and I hope most Male parents would ). In fact he has , walking in London a year or so ago when a child shot out from a doorway on his own and headed to the road. Out of pure instinct he put his arm out and stopped him. Fortunately the mother was just grateful but he was a bit worried at the time.
I struggle with parents who would scream and shout. An abductor is unlikely to have stayed around and stopped in a public area. It's my belief its usually embarrassment on the parents part but it's really not on to start having a go unless there is a genuine belief (like they are leading a child to an exit ) .
Ds1 once legged it totally unexpectedly just after ds1 and I came put of hospital after a traumatic birth. It meant although I pelted after him I was slower than usual. Had ds1 in the pram and he managed to for some God only knows what reason (he was three so being rational wasn't likely ) head to the ladies loo where there was a long line ( a day festival type thing).
I yelled " please dont let him get past you " ( if he had got in the actual room I'd have had to leave the pram unattended out of my sight as it was too big to fit in , or beg ds1 to come out (not a chance in hell that was going to work.
Now I realise it wasn't these other women's responsibility but all they literally had to do was stand in one place. Three of them literally moved to one side to let him pass (yes they absolutely heard me).
I was panicking ds 1 was out of my sight , I couldn't see whether he could get out the other side ( turns out he could have,,) (ok , stupid hormones fine, it had been a hell of a couple of months..ds2 had been born really early and had been in NICU while I was in ICU, I claim fair wussiness there).
Finally a bloody brilliant woman strode up , with a voice that instantly makes you wish to pull your socks up and fly right said " I've got your youngest ...look I have a son right here I promise I'm a mum too I will keep talking so you can hear me and you know I haven't gone anywhere. Get your boy".. I legged it into the bathroom (one of the women refused to let me step past and stood still...my saviour yelled "bloody hell dont be ridiculous you can see she's trying to get her son" which moved the woman. I grabbed ds1 who was just trying to exit the other side and into a massive throng of people I'd never have found him in ( and who was grounded for pretty much ever ) and dashed out, burst into tears thanking her. She smiled hugged me and told me we had all been there. She said she could see how young ds1 was and it would get better. Promptly boomed to the waiting queue " you should be all ashamed of yourselves , I hope noone helps you when you are struggling " and toddled off.
Now , I'm fully aware those women didn't need to help me but it is sad these at least 7 women in the queue didn't help , at all, and actively caused a problem. I do think this woman was a little harsh but I've often told the story of her, she had no idea the hell we had just been through and I was eternally grateful. As stupid as it sounds , after 8 weeks in NICU and 3 weeks in icu I was petrified of either child being out of my sight.
OP as uncomfortable as you felt at the time I bet that mother is eternally grateful to you...hold on to that