talk as little as possible and spin the event your way

First of all, social worker is there to "protect" the interest of the children. Therefore you have to spin your documented action (or over action) in such a way as doing it for the long term well being of your children. Never
voluntary give any extra information. Of course, you should
express remorse for your over reaction in dealing with your
kid. Remember, social workers are not your friends and there are many incompetent, over zealous social workers.
You need to guild them to reach a reasonable conclusion.