Here I will post links to laws that empower you against child & family services and give rundowns on each link.
This link gives more then a basic gestalt on what you can do and can't do. I will try to make things simple by giving situations which you can and should use one party consent law.
So if you have your kid taken away and your not sure why you need to record all phone calls and all meetings at first you should not tell them your recording because they walk all over peoples rights and have near zero accountability. Unless you have a record of it.
Video is the best witness. No one can argue with absolute proof. Audio is less effective so getting multiple tapes. Take note though if you record audio or video you must only record your conversations or you could go to jail.
https://ask.metafilter.com/270470/In-Canada-is-it-legal-to-lie-about-recording-a-conversation/amp
Here it says that you can choose to lie about recording them but also the one party consent law in its very wording means if one person chooses to record the conversation then it is legal. If they ask you are you recording and you say no those that like to walk on your rights will feel comfortable enough to do so. Those that do not have nothing to fear. A few years of this could get alot of bad social workers ousted from their ability to do so.
http://www.legalline.ca/legal-answers/is-it-legal-to-videotape-someone/
Now their buildings are public spaces and they are public servants. So you have the right to record them at work. You might not have the right to have audio unless you are party to the recorded video.
Here are the laws to help those find their voice to speak up for their rights. Here are the laws to protect you from those that seeking to rip apart your family. Here are the laws to defend oneself against injustice.
Are you ready to take a stand?
Do not capitulate to an organization that ruins families, creates serious criminals out of our youth, lies and deceives to cover its tracks and walks all over the rights of kids and parents alike.