Thegypsy, you are of course correct although the pension in question was a service pension which is taxed in its own right and not a state retirement pension.
It was still TC's job to tell HMRC. Mind you, given the time scale, the tax code would not have been changed in time.
A word of warning to others taking a retirement job. That too might also keep you in the 40% bracket at least in the year in which you retire. Although that job will also be taxed HMRC need to know of all sources of income.
Mrs PN at one time had a portfolio of 4 jobs in a year and with different tax offices now down to one plus 2 pensions. It was not unusual to get 8 letters from HMRC in one day. I now have 4 pensions, soon to get a 5th, and I can see the need for tax returns for ever more.