Answer:
1.) I wouldn't go as far to say he has a good attitude, but he does the bare minimum. He works, does everything he has to, and if that's all that matters to him, that's that. He's not negatively affecting anyone else or being inconsiderate.
2.) I would have owned up to it and cleaned it up myself instead of letting everyone else do the work. Also, I hope Justin didn't ignore he boxes even after telling someone else. As much as I hate when my parents use this kind of excuse when it comes to cleaning the house, it was his part to pitch in and help everyone too, regardless if he made the mess or not.
3.) It wasn't right for Justin to argue. I can understand wanting to be right in a situation, but they should've just worked it out in a calmer manner. If they really couldn't come to terms about it, why not just ask another co-worker or even the supervisor?
4.) Justin was completely in the wrong. He shouldn't have listened to the conversation in the first place, let alone tell everyone. It wasn't his place at all especially since it was <em>personal</em>. The only situation in which this probably wouldn't be as bad is if one of the people were planning on hurting someone else, as telling everyone would be for the sake of the safety of the group or someone else.
5.) I think Justin was definitely reprimanded and given a warning. It's wrong to tell events from a personal conversation so casually and act like he didn't do anything bad there.
6.) Based on Justin's previous incidents, I'd tell him to be more considerate of the group. He has to contribute as well, and even if he disagrees with someone, he still has to be respectful. And speaking of consideration and respect, listening in on that conversation and telling everyone was probably the worst thing he did. Even if he couldn't have gotten out of that situation, he was not in the position to go off rambling to everybody else.
Explanation:
I really hope there aren't right or wrong answers for some of these as some of these seem opinionated and I don't want to cause you to get a bad grade, but I tried my best!