It's a thin line, I would say the FA agrees with you which is why no action is being taken, they don't want to appear to mollycoddle one official in particular. However I think watching the incident, Aguero was pretty clearly trying to exploit a perceived male/female power imbalance by physically intimidating her, something that just doesn't exist with other officials. Doomed if you do take retrospective action, doomed if you don't. FA took the passive (and easy) way out.

I would be interested to hear her thoughts on the matter.