My officemate probably recorder our conversation. What should I do?

We went out after shift and shared our thoughts about our boss. Mostly negative. All four of us have said bad things about our boss. I noticed that one of my officemate picked up his iPhone. He then made a tight grasp on it and I saw that the screen is lighted up. First thing that came to my mind was that he's probably recording our conversation all along. Am I being diusional or should I be worried?

Overthinking it, probably. People pick up their phones for all sorts of reasons, all of the time. If he did record you, it's illegal to do it without your knowledge, particularly if he plans to use it against you. But I doubt he does. And how bad was what you said anyway. Bosses aren't stupid. All sorts of things get back to them that the workforce says about them. They don't care, because they are… Yes… The Boss. He isn't there to be popular, but to be… The Boss! Just relax.

With an Iphone you have to grasp it to turn on the phone. As said before people pick up their phones for any reason or no reason at all. You would have to ask your co worker if he recorded your conversation.
In the future be careful about what you say around him.

You are paranoid, but that doesn't mean you are wrong. Get a grip! You have to grip an iPhone to turn it on unless a notification comes into that phone. You can't record without opening the app/feature to record.

A recording without permission isn't admissible in court but if you are that worried about your bosses finding out your true feelings, you should keep your mouth shut. A recording would certainly be some proof but so would a tattle tail's verbal report. Trust me, your bosses probably know just from your body language that you aren't happy.

Worried

I do not think that you are paranoid. In the workplace, people are always looking for a way to survive or come into a promotion. Certain conversations such as about your boss should be avoided so that you will not have to explain yourself in the end. If I were you I will keep that stuff to a minimum and pay attention to this person behaviors. How many times has this person done this? I'm sorry to be the one to say it but not all people are good people even though they act like it. Office gossip is a setup and trap especially if you don't see yourself being friends with them long-term.

So he picked up his phone, and it lit up. So what. Unless you have reason to believe he would do something like that, I think you're just being paranoid.

You should have asked him at the time what he was doing.