Hiring process gone wrong

[MoominGang]

We're hiring for a new manager. Everything has been going well and policy followed. Myself and the other person on the panel made the decision and outlined next steps of going to the second interviews. This is where suddenly my supervisor is not happy with the decision, they weren't part of the process and struggle with letting control go. This put me under considerable stress and I no longer want to be involved. Would it be reasonable to withdraw from the decision making process on heath grounds?
Just to add that as a result I'm also thinking of rising grievance.

Seems overkill to me. Just say to your supervisor that you want to take a step back given that they have their own views on who to hire.

If they were struggling to let go, why didn't you involve them in the decision? Was this the first time you noticed this trait in them?

Those on the interview / selection make the decision based on the marking criteria as part of a fair and transparent process.

If someone has delegated that task they have handed over responsibility to others.

On what grounds did the supervisor want to alter your decision? I would be weary of unprofessional nepotism going on if they have a ‘ favoured candidate’. May need to get some advice from HR

Surely the supervisor can just be involved in the 2nd round? Alongside the existing panel. Seems like a lot of fuss. Not sure what's happening that's causing you this much stress.

HR has been involved during the process and I followed their advice. All hiring decisions have to be communicated with senior management.
This person has also complained in the past that they get no say in how I manage my team and set up 1:1s with them which make me look incompetent.

It sounds like the problem is the communication between you and your manager. You aren’t keeping them sufficiently informed and so they are overstepping to stay involved.

In this particular situation, had you spoken to your manager about the CV and first interviews? What are their concerns with the candidates you’ve put forward for second interview?

It would be unfair on the applicants if you pulled out now . You were at the interview , supervisor wasn’t.

You certainly can withdraw, but think - could you grow by actually handling this situation? Your supervisor isn't happy - is it your job to always make them happy? Or is it to deliver value to the organisation according to its targets and objectives?

Calmly doing your job, without overreacting to conflict (which inevitably arises wherever different people work together), will help you in your career. Follow your agreed process, involve the supervisor at the second stage, and draw a line under it.