Glad they are all doing better! IMO I don't put too much clout in the LFS comments about 'no problems". As you report, 'the ones she had or sold had no problems", but then 'she sold out and got more in". So her comment completely relies on people coming back and reporting problems. Through the history of retail, the amount of people who actually follow through with a complaint, like you did, is VERY low. I myself rarely go back with a problem, unless it is quite a pricey fish. Not that I have alot of issues along this line. But I did buy a severum long ago that I found dead in the bag two traffic lights from bringing it home! The LFS that I no longer go to insisted it was fine when it left and I didn't acclimate it properly. I argued with two people that the fish never even made it home, I turned right around and drove back, really? They even checked the clock compared to the time on my receipt! They finally gave me a credit which I used right away and very rarely go back.
I totally agree you should have passed on these, having nipped fins in the store. Sometimes I spend LUDICROUS time inspecting fish I want to buy. Somethings you can't see. Alot you can though, like fins, ich, color, behavior, dead fish in the tanks etc. Move on!