Well, I have a similiar problem with my friend's white's tree frog. I did tell her and I guess I didn't do very well cause we argued about it and then agreed not to talk about frogs anymore. We also don't talk about cat health care. She has five cats and feed them science diet...I am anti-science diet. She says that feeding them smaller amounts of science diet prevents them from being overweight and her vet recommended it. However her cats always act like they are starved. When I have to go over there to feed them when she is out of town, I feel guilty and want to give them more. Since she takes care of my animals if I am away and she cares for them the way I want her too, I take care of hers the way she wants. She has 5 cats and all of them have some type of health problem. One can't hold food down, another is always constipated, and one has a bladder problem and one has to have a special formulated food ause he won't eat. I gave her a list of the top 10 cat foods and she said hers was the best even though it was not on the list. I feed my cat one of the ones on the list and he loves it. It is the only food that I have seen him leave behind some. He gets full off of it quick because it has the nutrients he needs. I also discovered on the cat forum that feeding wet food once a day helps hydrate the cat. So I have a cat that has only been sick once (due to a bird disease) his litter business doesn't smell so bad and he is very active. I should mention that her vet just told her recently he discovered a new cat food that's out and very good. Of course it is one on my list But he also picked the most expensive one and one she can only get from him at the moment

Is your friend defensive about his pets? Does he act like he knows everything? Is he the type of person that thinks his way is best?

I did have another friend who had an incorrect setup and I told her if she changed a few things on her setup it would help save on vet bills later. I explained that even though her pet looked healthy that incorrect feeding habits and setup issues would cause problems later. She said she setup the tank exactly how she was told to 8 years ago, and I explained to her how we are still learning more and more things about animas and that what she learned 8 years ago was correct at that time, but now there are better ways to setup a bp tank. Same as how we are discovering some foods are better for us than others and how we are learning some things we thought were good for us turned out to be bad. I explained it is like humans eating unhealthy foods all the time and not excercising, and smoking could cause health problems even though they are healthy right now. That went over better than the frog issue with the other friend and second friend's problems were corrected.
The weezing could be a sign of problems to come if the tank setup is not corrected.