Great question for Meta; the FAQ you posted tries to avoid even more wordiness, so it apparently was confusing in this case.
We assume that the point of reading answers to questions on our site (no matter if you posted the question or somebody else) is to learn something new, with the least amount of reading and jumping around links. So, to decide whether two questions are a duplicate, we think about whether new information will be produced if both stay open. The wording of "same (potential) answers) used in the FAQ tries to express the idea that it's not the literal phrasing of the question that matters. But what they actually mean is that the whole set of answers is different. Or, in a second case, that the correct answer can happen to be different.
Example 1 (different question, same potential answers): "I wanted to make pavlova but the meringue doesn't whip" and "I wanted to make macarons but the eggwhites stay liquid". This hypothetical pair would be a duplicate, because the troubleshooting of whipping eggwhites is the same, no matter if you want to use them in a pavlova or in macarons.
Example 2 (similar question, different set of potential answers): "My custard curdled, how do I salvage it" and "My custard curdled, how do I prevent it from happening next time". It sounds like the same problem, but the steps to make a good custard are different from ways to salvage an already curdled custard, so we usually don't close these as duplicates.
Example 3 (same wording, same set of potential answers, but different correct answers): "Please identify this kitchen utensil" posted twice, but with photos of two different utensils. The set of potential answers is the same - any term that labels a kitchen utensil could be an answer. But we assume the correct answers will be different, and don't close as duplicates.
In your case, I'd say it's a clear duplicate. The potential answers are "it's safe" or "it's unsafe". It so happens that both opinions have been posted under the different questions. This isn't ideal, because you now have to make up your mind whom to believe. But even with a question where all answers and votes agree, correctness is not guaranteed.
Ask yourself: if you post a new question and we don't close it, what would be the consequences? The four possible scenarios are:
- You get no new answers. You wasted your time. Any new person finding the question also wastes their time.
- You get a new answer ("safe" or "not safe"), which doesn't contradict the old answers. (I'm mentioning this scenario for completeness - it's no longer possible in this situation). You get no new information. Any new reader wastes their time reading the same thing twice.
- You get a new answer ("safe" or "not safe"), which contradicts an old answer. Now you don't know which answer is wrong, the new one or the old one. Any new reader either overlooks one of the questions and misses half the information, or has to waste their time hunting up two questions and switching between them to compare answers.
- You get a new answer which is something else than "safe" or "not safe". It's likely not a real answer, if it doesn't address the actual question. But even if it turns out to be some long explanation that claims to settle the controversy, its place is under the old question, where all the other answers are, not under the new one. (If you're afraid that nobody will answer an old question, add a bounty).
If (as an example) it depends on the type of mold
If this were the case, it should have been in the answers of the question that's left open. Again, if you think that the current answers are incomplete, add a bounty. But in this situation, it's quite certain that this isn't the case. Food safety rules are intentionally made as simple as possible. Nobody expects (or trusts) a layperson to do species identification based on visual appearance. It either is normal and expected to have mold, or it's a sign that the process failed. Asking the same question a fifth time won't help you find out which one it is.