The Bulls were two goals down with just four minutes on the clock, and a late consolation goal from Steve Guinan - a former Scunthorpe loanee - made the scoreline look better than they deserved.
"We got caught cold. We made some basic defending errors," he said.
"It's not very pleasant when that happens. It was one of those days when they are flying in from all over the place.
"It's an unforgiving league. Once you go higher you get punished for any mistakes and you get punished for being out of position even only by a yard or two.
"It's no good slaughtering the players - there was a lot of honest endeavour - but we had great difficulty contending with their front players. We couldn't control them."