Reading this, I can't help thinking that she did the right thing.
He did look unhappy bless him, and as you say - he's fended for himself for so long it must have been distressing for him not to be able to exercise his usual freedoms. As he hadn't settled to any degree, letting him out is, I feel, a kindness.
And at least there's one freedom he won't be exercising.
I do hope thugh for his new Mum's sake that he puts in an appearance and lets her know he's okay. I love having a cuddly cat - it's great, but I spent 20 years with one who wasn't fond of cuddles, and I know how easy it is to love the un-cuddly sort too, so sending her hugs, and hoping The General wanders past soon for some fud.