OSU-Central Michigan finish

[DadofTwins]

Soccer guy chiming in with a probably-dumb question:

The rule says there is an untimed down unless the foul is on the "team in possession." Since it was 4th down, the play ended with a change of possession. Does the phrase "team in possession" refer to the team possessing the ball at the end of the play (as in, the defense intercepts the pass and the returner gets tackled by the face mask on his way to the end zone) or does it only refer to who is in possession at the snap?

Or, am I misunderstanding something about when and how possession changes after 4th down?

Thanks.