Pardew thought the reason why Newcastle folded so dramatically was because unlike Arsenal, who had their game against West Ham called off thanks to a Tube strike, his team had to play a draining Boxing Day clash at Manchester United.
"I honestly think that would not have happened. We certainly wouldn't have had a scoreline like we had (if Arsenal had played on Boxing Day," said Pardew, whose side now sit three points above the relegation zone.
"The (difference in) energy levels between the two teams was evident at the end.
"One team was energised, the other was really leggy.
"That's why we ended up with score that we did."