Gordon is someone Ritchie dredged up in a hurry - Phil phoned her and said 'II need to buy some time.' He needed Sharon distracted from the loss of the Albert, and miraculously finding her dad does just that. Phil gets a breathing space to get Vincent out of the Albert, and Sharon gets a reunion with her 'father'. Ritchie has probably paid Gordon to say whatever Sharon needs to hear.
Phil is clearly protecting Kathy by not exposing Gavin as Sharon's dad.