Read the full account. No rational mind could conjure up a conclusion so absurd as that one.Zech. 12:2-9 is pointed at the remnant of Judah and the faithful of Jerusalem. God protected those Jews who received the gospel with a true heart and His new church or body under Christ during the siege.
Not to mention that the Zech 12 prophetic account is repeated and amplified in massive quantities by everyone from Moses to Malachi.