A 'Serindipitous' occurrence

On Tuesday 5th November hearing of Rob M spotting a female Serin at Corton OSW, I walked down the west side couldn't see anything in the fading light as it was about 4pm, as I walked around the east side aside from 3 Linnets, Goldfinches and Greenfinch I spotted the shape of a smaller dumpier bird with domed head and short deeply forked tail flew up and it flew to the south- east corner of the OSW, presumably to roost in the Tamarisks. I suspected it was the female Serin. The very next day, Wednesday 6th November, I walked around around the west side of Corton OSW & at 7.50am I saw a bird fly into a bush near the north-west corner of the OSW from the compound, it looked very promising. It then flew again with some 4 Goldfinches and flew to the Rosebay Willow herb tall weed stems on the west side of the path. It was the fine female Serin. In flight it showed a deeply forked tail and noticable and prominent lemon-yellow rump. When it feed it showed a deep streaked body (above and below) only becoming unstreaked with the underparts near the undertail coverts white and unstreaked. It showed 2 faint wingbars. The pale breast, there was a tinge of yellow on the middle of the breast. Crucially, there was no yellow in the tail. It often spent time feeding behind the tallest stems and was obscured for most of the period of observation. After only 3 minutes for no reason the entire flock flew east towards the sewage works compound and sadly the female Serin wasn't seen again. About 20 minutes, later Andrew E arrived, then Paul & Jane and Maurice and finally Jeremy, but despite the additional observers present we couldn't relocate the bird. POSTSCRIPT: Later on amazingly Rob M found a female Serin at beach farm Benacre, was it the same bird that had moved on?