If you want to use "often don't work properly" as an argument, then people are allowed to challenge that argument.

I guess they shouldn't have assumed you were speaking from experience, but I don't think that's a big deal. That's not forcing you to accept any conclusion. If it happens "often" you should have examples and/or data. If you don't then maybe you should reconsider if it actually is "often".

And they directly asked for data that it doesn't increase safety.

That's not unwillingness to see your point of view. If you provide quality evidence, you can win them over.