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.