Why not just leave things be for a bit. The truth will come out shortly and if one of them doesn't contact your daughter, then it was just a spur of the moment thing.

I think you need to allow your daughter to make her own decision as to whether she wants to block him/her or not.

Again, give it time...nothing may come of it and for now, let it go...

Sit quietly, the answers will reveal themselves when you least expect them to.
The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.