Exactly what I would have done, Erika!
I have a similar story but with a dog. Our Lhasa Apso, Syau, is obsessed with squirrels. Our 4 daily walks are mostly squirrel hunts for her. She spots one, lowers her body and slinks forward until she believes she’s close enough to lunge for the little critter. And, she does. And, they always get away.
One day, she bounded into some bushes after hearing the rustling of a squirrel but quickly backed out, looking confused, first at me and then at the bushes. I saw something emerging slowly. It looked like a squirrel but why was it not running? Why was it coming toward the dog?
Syau looked frightened and backed up more. I pulled her leash close and ventured forward. The poor squirrel was dragging himself, his back legs not working, probably the result of a car encounter.
Here Syau had her chance to finally get a squirrel and she was frozen with confusion and, it seemed, concern.
I took the squirrel to my vet, where he was treated for his injuries. The doctor didn’t think he’d recover well enough to be returned to the wilds of a residential neighborhood so he was adopted by a wildlife sanctuary.
Now, we know it’s the chase, not the catch, that Syau lives for. Seems to also be true for your cat, Leo!