I'm not a lawyer but I don't think negligence holds up well as a defense.
If the FAA is unhappy with what you have done or someone else who is loud enough is unhappy with what you have done, they can bend the loose definition to fit the situation. Look to Trent Palmer for a recent and pretty public version of this.
If the FAA is unhappy with what you have done or someone else who is loud enough is unhappy with what you have done, they can bend the loose definition to fit the situation. Look to Trent Palmer for a recent and pretty public version of this.