I am quite sure that the players didn't sit back because GH told them too. I think it's more a matter of confidence at the minute, or should I say lack of it. Even GH said, the team are actually pretty good and should start believing it. Probably what went through the lads minds at 1 up was, "Hey, how can we be winning here? This aint right!" Anyway, that's just my opinion.
On another matter. Warren needs to play at left back I'm afraid, at least until Scotty is fit. How about starting with Whalley on the left, class act who unfortunately seems as capable of lasting 90 as Carlos. Then, bring Carlos on in the second half if things need shaking up a bit. All a bit Championship Manager I know, but surely makes sense given what we've all seen recently.