It would have been very obvious to a chef that the raisins hadn't been plumped.
Avoncino couldn't have know that the carpet had been destroyed, since it hadn't been reported to the police, and therefore wasn't public knowledge.
Manuel says that turmeric and saffron have "about the same flavor". This is incorrect. Saffron has a more refined, savory flavor, while turmeric is very pungent and odorous, and it can repeat afterwards, where one can taste it again in a most unpleasant fashion. Saffron is as delicate as it is rare, and for discerning palates. Turmeric is as overpowering a flavor as it is common, and anyone can afford it, therefore it shows up in many dishes. Saffron is dainty and elegant, turmeric is odoriferous and lacking in sophistication. A professionally trained chef like Manuel should know there is no commonality in taste between the two.
Manuel claims that the mistake of the wilted cilantro is the fault of the grocer's delivery, and that he'd asked for cumin. Cilantro and cumin have no commonality.