When you let it be recorded and the recording be possessed by someone else, it's practically public, as you can't control what'll happen in future and there will always be mean people that'll try to bully you for that sort of thing. I'm sad that it's caused you harm, but I guess in such situations showing confidence might work.

So basically, you bet that people would overcome millions of years of human psychology?

While I agree with you it would be nice if that happened (really nice!), i wouldn't expect that to happen for a long long time.

Hope you found a better job and colleagues after that.

You expected them to compliment you. It means you are proud of what you did. But if you really are proud of what you did you wouldn't care about their opinion in the first place.

So either you are somewhat ashamed of what you did and regret that it became public or wanted to brag with it but are now angry that you colleges made fun of you instead.