This happens to me both when I go to the Music App and when I play the song directly from my iPhone issue headphones using the pause/play button just like I always used to do with old iOS 6 versions. It doesn't play the song it was playing, and jumps playlists (sometimes what I had to what it decides to play is very loud and surprising!).
If I hit the control center though, the same song is there, but if I play it from there that doesn't guarantee that it stays in the same playlist, just that the same song gets played.
I am still testing to see if the recent 7.0.2 update has fixed this or not.