This may be what happens CATSA Screener -- and I am not saying that you are lying. But I experienced first hand:

a) An agent in YOW who was bullied by his supervisor to send me back to check-in and to the back of the line because I had two pieces of carry on and a small plastic bag with my keyboard in it (the agent had passed me through and he protested on my behalf but the supervisor basically said, do you want to keep your job? -- but not in these words). I basically asked him quietly, of course, is he normally like this, and he said, partically bad today. So, I just complied and thanked him and wished him luck.

b) An agent in YHZ who insisted that I stuff my third paper bag (holding a box complete with a chocolate sculpture -- I'm not going to disclose what it is...). He said he knew it was dumb, but he didn't want his supervisor clamering down on me and he didn't want to get hell. So, I said ok and complied. Smiled and wished him luck. Of course, as soon as I left, the bag came back out.

c) An agent at YYZ when taking apart those batteries tried telling her supervisor that the batteries wouldn't be touching each other if one was in a plastic container and the other one was out (ie. she was sympathetic towards me). But the supervisor would have none of it.

Now, these three examples -- does it not tell you something that supervisors don't listen and don't care to be challenged?