Possible but. Usually this is uncommon if the tooth is healthy. It is possible for tooth enamel to come off after a routine cleaning if there is decay or a fracture on the tooth.
Cavity. I can only think of one possibility of enamel to come off after a routine cleaning. Cavity, if there is cavity that weaken the tooth, enamel can break off. This can happen spontaneously when the enamel is undermined by the decay.