As employees of whatever company holds the conference, both men were legally considered 'on duty' while at the conference, and were subject to said company's rules of conduct.
Why she did not turn to them as she would have in the workplace and reminded them that 'We really can't talk like that, here', I do not know, but an alternative was to anonymously e-mail whomever was in charge.
Her observation was correct, her handling of it was over the top.
I work for a big company which holds a BIG convention each year.
We are expected to wear our I.D. Badges, business dress or uniforms, and behavior standards are the same as when we are on duty in our respective facilities.
This is made quite clear to us.
These gentlemen must have known that they were over the line.
If this happened during one of the yearly assemblies from my workplace, and someone in management overheard it, believe me, it would be corrected on the spot.
Sylkat