Deleted on snapchat or not?

So I realised that I hadn't seen someone posting in a little while so I checked to see if I had them on my list still, there score was there so I assumed I was still their friend, then a few days later their score had disappeared, I guessed I had been deleted so deleted them back but they then appeared in my people who added me list. I checked my friends list again and there were a couple of others like it, 1 didn't appear in the added me list but another did. What does this mean?