^^^The plot requires that the maid be stupid. Sure, it's possible a convenient idiot is at hand, but it's still convenient plotting.
The possible consequences (theoretically ranging even up to war) are precisely why real spies don't go around committing murder and mayhem on the citizens of the target country. Defectors, yes.
And for those who confuse covert operations with intelligence (in both senses of the word,) covert ops are directed against the civilian populations just as war is, because that's what covert ops really are: War. And they are directed against weaker powers without powers of retaliation, which is not the case in this series.