OK, maybe some cats do need Prozac...
Well, as there's nothing to the story that harms the realm [it is in Great Britain], or harms anything or anybody else, one could suppose that there's nothing wrong with this picture.
So it wasn't the drug so much as the tomcat removed from the tabby's life.
I wouldn't be too excited to go back out for awhile either. Sounds like ole' Twig got the slapdown. If this happened to my cat you can bet we would do everything as a family to build her back up and get her back on the saddle. Sounds like it is a good thing the Tom left. They can really screw with even the most confident of cats. A broken tail . . . dang, who wouldn't be a bit down for awhile? We've all had minor incidences similar to this. I think it is called character building in humans.
Sounds like they were drugging the wrong cat.
If the bully cat moved away, they can take the poor kitty off of this prozac now....
I treat a good many cats with amitryptyline. It really helps when a cat is territorially marking when an outside cat is threatening them and/or their territory.