When I was crossing the U.S./Canadian border in '86, they asked those very same questions to me. I just complied and I never got that treatment. My name, address, age, where I was going in Canada and how long I was going to be there. I told them it was my first time visiting Canada. I even had to show them identification. This was in April of 1986.
I feel the man who was placed in a holding facility should have just kept his mouth shut and answered the questions from the officers instead of getting outright mouthy and getting into a shouting match which resulted in him and his wife being charged with "assaulting" an international border officer. Those officers were trying to do their job! I know of those Canadian border patrol officers. They just don't play around at all. Just answer the questions and don't raise your voice and there won't be any incidents.
I wish that we had those same border patrol officers asking those very same questions on the Southern end of the United States to question those coming in illegally! We would never have had a 9-11 had our borders been properly secured.
It's becoming a police state because the powers that be (like the former administration) are allowing terrorists into this country and allowing them to bypass these international checkpoints. And this is what really angers me! It makes absolutely no sense for the U.S. Canadian officers to be taking this responsibility by themselves. We need this on the Southern border too!
From what I listened to on that audio clip were the following facts:
Officers pulled man and his female companion over.
Officers claim they have "no grounds" for pulling him over.
Officers claim they were "assaulted" by the man and his female companion when the man resisted arrest and was in a verbal exchange with officer. It is never a wise move to argue with any law enforcement officer (whether they are state or local police or border enforcement). In arguing and resisting arrest you escalate incidents.
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Should the officers be sued in their individual and official capacities, they will have the burden to prove the man "assaulted" them. I will leave that for the attorneys and court to decide what is considered "assault". The audio is prima facie evidence! Never argue with law enforcement even if they are in the wrong. What that guy should have done is kept his mouth shut and then take that officers name and badge number and filed a formal complaint.
Those officers may have acted too rough. However, the man and his companion didn't help to mitigate the situation. I don't know about the man's companion as I heard on the audio that she physically "assaulted" one of those officers. Not good!