I don't think the FA can be arrested for filing a false police report. In the time events transpired, I can't picture the FAs signing any piece of paper swearing to the statements as truth.

Hope ATA comes down on the FAs for this, but I doubt it will happen. Likely what will happen is a "re-education" on the policy and nothing else. Anything FAs do to report things to the police will likely fall under the "terrorism" BS and they will get a walk.