If you leave a seniority list that's it. You cant just say sorry that was a bad idea and come back, otherwise where would it all end
Maybe not, but this is an exceptional case and I'm glad commonsense has finally prevailed.
Despite that, I understand the contract is yet to be finalised and I'm pretty sure as much as BA may be happy for Pete to retain his original seniority, they will be very reluctant to bring him back on PP24. There is also the fact that he walked away with a significant amount of redundancy, which again the company aren't just going to write off.