Is she?
She published this joke about sexual humiliation from the same conference:
https://twitter.com/adriarichards/status/312265091791847425
And the company she was envangelising for on that twitter feed thinks that a visual joke about photocopying your genitals is not inappropriate for their jobs pages:
http://i.imgur.com/uWc8P39.png
I understand that speaker and context make all the difference, but she made a joke about sexual humiliation to thousands, and then, at the same conference, got offended by overhearing joke conflating dongles to genitals.
I agree with you that resorting to sexual slurs is immensely counterproductive and makes one look stupid, but I can also understand why angry people would reach for them, since this is in the line of the discussion. Understand, but not excuse.
Still the point stays - you don't make penis jokes and then get offended by penis jokes.