Good news, everyone.
Ref: http://animalcare.my/2011/04/injured-kitten-with-broken-paw.html
Sofie said there are no external wounds and the cat (whom she now calls “Toothless”) reacted by trying to bite Sofie when she pinched his paw. So this confirms that it is probably either a deformity or an old injury and nothing needs to be done about it.
In fact, Sofie said Toothless has been doing the “cat massage” on her!!
So glad we sourced for a second opinion before doing anything which wasn’t really necessary.
All’s well that ends well!