Is there a likelihood that P was hovering over life and death when AarYa went in search of Ansh?
Perhaps Dupey needed the money to treat him and got in cahoots with SP who provided him the finance in exchange for being the go-between SP and the hirlings (read Akash) & AarYa? Part of the deal was Shobha would be kept in the dark and in case of failure Dupey would be the fall guy..
SP's deadline date to get Aarti-n-Ansh out of Yash's life was Feb 1 as per his vachan to G3.
So SP sets the ransom demand re: AarYa divorce and Yash remarriage as per his timeline. As far as Dupey is concerned, he is OK with SP's plan as Aarti and Ansh would get back to P.
However Yash pulled a fast one by keeping his cards close to his chest. After his run in with Akash he never revealed his plans to anyone including Aarti. So no one was aware of the chemically treated ball.
Once the divorce papers were signed and Yash was participating in all the marriage rituals - it was unnecessary to hold Ansh captive. So Akash was sent to release Ansh and return him to AarYa. Unfortunately meanwhile the chemical ball did its work and Dupey had the adverse reaction. So Yash could walk out midway between the pheras and escape the remarriage clause.
This explains why Dupey could apologize and exit without having to hear "boo" from SP.
One thing was obvious after the Dupey's left - SP was seriously perplexed and stayed back alone before finally returning to the mandap.
It also provided the CVs an opportunity to stay with their original track of Ansh's kidnap and P's involvement while giving them the luxury to bring P back in AarYa life later down the road if they choose to do so.
Overall it was a win-win situation for the CVs, they got to introduce Akash, P's final exit was never shown so there is a possibility for re-entry, SP's hands were kept clean however with a question mark in the minds of the audience, and now they can transition smoothly to the next track. They also got a bonus in that the TRPs are increasing!