It was my first app ever(the account is registered to my limited company) and it is in the Health&Fitness category. It has some social networking functions and the issue was that the users could start talking with each other without approving the other party, a bit like the chatroulette, and the reviewer explained that the users should be given a chance to choose if they want to talk to this person before they receive the first message. He suggested me, at least to show a profile picture and a name and ask if the users would like to match.
I closed the phone and 5 min later I received the rejection together with the talking points that we went through on the phone.
I also suspect that Apple is trying to make sure that the same app is reviewed by the same employees. I think I dealt with the same 2 people in multiple review issues in later updates.
Sometimes it was frustrating when I have a rejection about something that was previously approved but it was resolved every time when I explain the problem and the solution in the notes to the reviewer section. I think I have a friendly reviewer that sends my updates straight to the store in 6 hours and there's another one who is being hard on me and needs to be convinced every time. Regardless, I am happy to be able to explain things to people.