Arushi's words ring more true I think that he does things spontaneously, passionately only to regret afterwords..
My spec is that tat is removed and that he will sign the papers as this is the route CVs are taking so that P can have her moment to prove her innocence..
How will she is the question:
Only way is that if papers are signed by someone else and comes to TN to prove to K that amma is behind the breakup of marriage...Amma is check-mated as K has not signed and realises what amma has been doing all this time and also proves P's innocence...