Your chair and v chair appear to have acted unilaterally and possibly beyond their authority.
Even if the 2 of them are the HR / employment committee it should not be the case that they are authorised to act for the PC in such an important matter.
A committee may make a recommendation to PC but it should be a PC vote.
Best check your SOs to see exactly who is appointed and what authority is delegated to them.
The PC should not be bound by such actions if they are unilateral.
They have held themselves out as representatives of the PC and could have inferred unfair advantage upon 1 t and unfair disadvantage upon others (potential job applicants.)
On the one hand this appears to be a clear case for monitoring officer to investigate code of conduct breach.
Also, if sufficient Cllr’s are agreed, a rescission vote could reverse it.
Similarly of concern - the person that has been appointed is likely to have known that the procedure for their engagement is potentially unlawful and inappropriate. That's not a good candidate to be taking responsibility for future corporate compliance, proper officer and RFO responsibilities.