Me and my Dad saw an Egyptian Goose at Splash Point on 14 April 2009 last year as well, It flew NE and was seen soon after by Matte Eade and Bob Self over Seaford Head. Perhaps the same bird on all three occasions, as they are are far from common in this neck of the woods.
I saw a pair down in the cuckmere haven near Litlington. Has been flooded for most of the winter so excellent for geese and duck. They stand out as an interesting bird as haven’t seen them before around this area.