Derby County 1 Preston North End 4
Jewell described the first-half performance in the third round replay at Hillsborough as unacceptable but he witnessed a repeat in a tie that was an embarrassment for the home side.
Derby are set to unveil new American backers on Monday but they must be wondering what they have signed up for because the club are in free-fall on the field.
Preston outplayed them and the scoreline did not flatter a team that are in the relegation zone of the Championship.
Karl Hawley scored twice and Simon Whaley added another before the break, and although Derby briefly roused themselves in the second half, the Lancashire club deservedly booked their passage to the fifth round.
Derby were so bad that they were booed off at half-time and again at the end by the fans who had not already left Pride Park in disgust.
The Preston supporters loved it and it was hard to believe they are struggling so badly in the league on the evidence of this impressive performance.
Chris Brown was outstanding in attack, Darren Carter and Paul McKenna dominated the midfield and former Derby defender Youl Mawene was the dominant and composed figure the home side glaringly lacked.
Derby's defending was pitiful with the experienced Andy Todd making two errors for Hawley's goals while Claude Davis had another desperate day against the club he played for with such distinction.
Jewell's team had come back from two goals down against Sheffield Wednesday but there was no escape this time after Hawley side-footed the opener in the 14th minute when Todd's back-pass fell to Brown.
Carter cleverly set up Whaley for number two in the 33rd minute after Brown had sprung the offside trap and Hawley made it three in the 45th minute after Todd failed to cut out Brown's square ball.
Derby's record signing Rob Earnshaw got his first goal for the club when Gary Teale sent him clear ten minutes into the second half and there could have been hope for the home side if Robbie Savage had scored seven minutes later.
But Preston always threatened on the break and after Mawene and Hawley had missed chances, Neil Mellor completed the rout from the penalty spot in stoppage time after he had been sent sprawling by Lewin Nyatanga who, as the last defender, was red-carded to complete another desperate day for Derby.