We don't know this person, or this shelter. The only information we have is what you have provided. Frankly, that statement that the person doesn't want to give the shelter money, and wants to just grab the cat and run sends up a red flag. There may have been other reasons why your friend was turned down, there's no way for us to really know that. Many people here work in shelters, and have been on the other side. They are going to have a different perspective about this than you do. Yes, people will go through the interview process, even if they don't have the best intentions. It happens all the time. So when red flags appear for whatever reason, shelters use an abundance of caution.
You don't live anywhere near this shelter, so any information you get about its reputation, or the story of the dog with the broken leg are really just heresay. Maybe it's true, but maybe it's not.
One thing I can almost guarantee you though: more animals are alive and well today because of this organization your friend wants to steal from tomorrow. They have saved many lives - don't forget that.
Please tell your friend to calm down, get a vet's name, and try to reason with them the fact that the kitty is 8 years old, and that his reasons to have a kitty are legitimate, etc.
What is his living situation? Who does he live with? How old is he? Can he afford a pet? Does he live with his parents? If so, are his parents in accordance with him adopting the kitty? You said he wanted THAT pet so badly - how come? How did he find it?
Remember that the shelter might not adopt to him if he doesn't have all of the above in check, as it would be highly possible for the kitty to be back...
Please, try to pull yourself from this situation and guide your friend on the right direction - what he is about to do is not going to be good to anybody, including himself.