I fed TOTW at one point; no problems, however, no, I do not really trust anything by Diamond. But you'll find stuff wrong with EVERY food... but yeah TOTW *is* a Diamond food, it's not simply manufactured there, and it tends to make me nervous. However it's a seemingly great food, and does well for a lot of dogs who are on it. Any companies involved in the melamine recall are a bit scary, IMO. From what I've read, there were likely thousands of deaths, not counting the animals that were sickened, but it can't be confirmed because there wasn't a government database where animal deaths could be registered.
There were so many companies involved, every last one of them put profit before the health of thousands and thousands of loved animals by putting in their food the cheapest nastiest chemicals they could source. There's also been a few FDA reports following the aflatoxin outbreak, moreover those people are also not aware of the recent recall on cat food that killed some cats or the "unofficial" recalls on TOTW over the past few years.
Rarely is a dog food made "in house" and most use others plants and are owned by large companies (Nestle, Mars, Diamond, etc, etc). Some of the only foods that come to mind who have their own plant are Fromm, Champion, Lotus, etc. Lotus actually made their own cannery because they did not find any of the other ones acceptable (most all canned foods are produced at other plants, it's why Champion does not have them, they refuse to use another plant and don't want to build their own).
I don't really trust ANY dog food company 100%. It's a matter of going with what you feel is best for your dog and what works best for your dog. But try not dissect EVERY little comment made on dog forums and dog food websites. Certainly if a company has had a lot of problems, similar or whatnot, there may be something going on and it's smart to stay informed, but there's always going to be at least ONE bad comment about every food out there.
At some point, you have to let go as a consumer. You can only do so much homework as a consumer and not a whole lot more. Unless you can watch their entire manufacturing process, from all sourced ingredients to finished product, how does ANYONE KNOW about ANY food? We don't really... gosh, we could go to the lengths of finding out what kind of GRASS the cows were eating where the meat came from. Was it purified WATER that they drank? Look, I really really love Champion Pet Foods for the most part, but they aren't perfect either, and I accept that. Overall though I feel very safe using their foods.
Basically, as consumers and dog lovers, at some point, we have to make some educated "guesses" and best "hunches"... maybe it's not scientific, but I see certain results with my dog on certain foods, some better or worse, than others. I get certain vibes from some companies, bad and good. I probably know WAY too much about dog food than is necessary
but I truly want the best for my dog, and I think we all do, and just go off that....