What is the name of your state (only U.S. law)? Florida
In this day and age where the ability to record anything, using your phone is prevalent, how does that work with an "all parties must consent" work? A case of someone being bullied was recorded by another student. This student is 18. The other two were under 18. Recording took place in school. Principal says that nothing can be done unless posted onto social media.
The principal is not quite correct.
The crime comes with the act of audio recording without consent. There is no publication element required.
Video recording on its own, as long as it is done in a public place and no privacy has been invaded, would not (generally) be considered a crime. But there are always exceptions.
And, under the described situation, one of the exceptions could apply here.
While a police complaint over the audio recording could potentially be filed, and the police could potentially pursue the person who audio-taped the bullying incident, there is generally no injury or damages unless or until the recording is published, displayed or distributed to others.
The publication element, as a note, would not be limited to just an online, social media display.
But, if there is an audio/visual recording of a bullying incident, the principal should have confiscated the phone and turned it over to the police for investigation - more for the bullying and who did it and why the person who recorded the incident didn't report it immediately, rather than for the audio recording.
edit to add:
For recording laws in Florida, you can visit the following Digital Media Law Project site -
http://www.dmlp.org/legal-guide/florida-recording-law.
For a good discussion on Florida's anti-bullying law, you can visit the following site:
http://www.florida-lawblog.com/2013/07/florida-anti-bullying-law.html.