I had my cleaning lady wash my meat and dairy dishes, when i come home i noticed that one of the dairy dishes is in with the meat dishes, what is the din of the keilim? And if possible to give a source.
The dish remains kosher after the fact.
The Rema (95:3) rules that if one finds a dairy utensil among meat cutlery, one need not be concerned that it was washed in a way that would make it not kosher.
The Taz 95:13 and others point out that there are many reasons one can assume that the dairy spoon was washed in a permissible way. For example, maybe the spoon wasn’t actually washed with the meat cutlery. Or, maybe the dishes were clean of residue and at least one of the types was eino ben yomo [over a day after last use]. Also, maybe the water didn’t reach yad soledes bo, i.e. it wasn’t hot enough to transfer flavor.