Despite twice leading the encounter, poor marking let the visitors back in it, before Sone Aluko condemned the Magpies to defeat.
Pardew believes it was basic defensive errors that cost his side dear, and the chance to go second in the Premier League table.
"We seemed to drop down a gear today," he said.
"In the end there were too many opportunities for Hull, we have to tighten up, and find the consistency of performance that we are searching for."
However the Magpies' manager was full of praise for the visitors, and thought they were good value for their win.
"I have to pay tribute to Hull, they did a lot of things very well today," he added.
"We had a chance to pinch a point but it just fell to Loic Remy a bit quick, but you can't take anything away from Hull, they deserve the plaudits.
"We have to regroup and make sure we're ready for the next one."