I dont remember the Stones at 'The Downs'. I have many memories as I went regularly. It was absolutely packed the night 'The Who' were there. As to its location it was on the keymer road almost opposite the ockley lane turning. I believe it is now a housing estate.
I agree with your first paragraph, Connolly was stumbling but did get a hand on to his back from the defender and even more entitled to go down than the Palace player.