So you think Gorrin saw Godden run past him from midfield (from a way away, not even close) and thought - "ah, he's number 9, and their main goalscoring threat, so not my problem"?! That's crazy, it doesn't matter who the players are, if they're in your position and no-one else is around, you deal with them. If Godden was out wide should the fullbacks not tackle him or cut out his crosses? If a striker is out wide should the centre backs charge out and tackle them?
I'm not sure what Moore was doing, yes maybe he was at fault, you can't really see him in the replay. But Gorrin clearly lets the runner through from midfield, a runner who is right in front of him. Dickie then has to leave his man to deal with this new threat. In this specific instance, he makes a defensive error which leads to a goal.