While I don't have IT experience, I can tell you as someone that both worked as an electrician and a FiOs technician that I also assumed that honesty reflects well on people and would be careful not to discourage it. I started at Verizon at like age 20 with that attitude and had no record and seldom anything to hide.
I learned fast that the policy of managers in both companies was, "Encourage narratives that honesty will always result in a better outcome to all employees... And for those stupid enough to believe it, punish them severely because only when they're honest do we know with certainty they're guilty."
First time I was questioned by management at Verizon, I made sure I was ambiguous in a way that made them think I was guilty. They said I was fired immediately and I said, "I'm fired? For what? I wasn't even in the truck. I told you what happened and I told you I was up a pole. The bucket truck was 2 blocks away when I saw it all."
Their faces turned white as they realized that I can tell everyone it's a lie and they can't just dismiss me as disgruntled for getting fired.
Why did you do that?
Another thing to consider is that the outcome (which is the one I wanted) resulted in me having them by the balls. I could repeat it to them as retribution in front of other employees with records to back it up and even in front of higher management to demonstrate how grossly incompetent they are.