QUESTION: X shouts at Mayor Z, "Buwaya!" What crime, if any, was committed?

During the speech Mayor KOKO DAYL, a constituent, Ms. ASH HARDYN shouted, "Buwaya ka! Buwaya ka!" She was probably referring to the alleged irregularities in the handling of city funds.
KOKO ordered his security guards to effect a "citizen's arrest" on the person of ASH. Immediately, she was surrendered to the nearest police station.

[a] Was there valid citizen's arrest?
[b] What crime did KOKO commit, if any?
[c] What crime did ASH commit, if any?