i Also he was catholic and stayed one while all around him changed.
tp I did not hear the programme you mention, but I would seriously question this one if you mean he was what I would call a Roman Catholic. His favourite royal patron was Queen Mary II (or at least his odes and funeral music for her are his most impressive royal commissions) and she was only Queen because her father, James II, had been forced to leave the country due to being a Roman Catholic. In that sense he was clearly supporting the Protestant establishment.
It was a period when there was hysterical suspicion of Roman Catholicism, and I cannot imagine Purcell could have retained his position as organist of Westminster Abbey if there was the least possibility he was not a good Anglican.
However, there is an interesting comparison with Bach as regards the church texts they set. (This probably only reflects the choice of text by their employers, but does indicate their religious milieu.) Whereas there is a definite protestant tone to the text of Bach's arias (lots of personal devotion to Jesus), Purcell's church music as far as I know only set words of scripture and the services of the Church of England.