There has to be some "come back" on these type of accusations.
Say a Skipper has reason to chastise a ramp agent driver etc. said individual then says OK I'll ruin his day and reports him for supposedly smelling of alchol. (In a commercial world can be used to delay your competitors flights) If it proves that the accused person is totally clear he/she should have redress on that individual for wrongfull accuzation. Does Libel Law cover this as Pilots being proffesional it would be a slight on their character (no smoke without fire etc)
Unfortunatly in the genuine cases I would not like to surpress the honest concern of an individual.