When giant Raiders winger Edrick Lee flew through the air in the 76th minute to latch on to a Campese kick to score it sealed the Warriors' fate as Canberra pulled off their second come-from-behind win in as many weeks.
"I thought Campo's poise ended up being the difference,'' Elliott said of the five-eighth.
"I felt pretty confident about our D. They didn't look like penetrating it then they scored one try after they had four or five sets in a row.
"Unfortunately the errors that we made were individual skill and two really poor decisions on shift plays to try and promote the ball and it doesn't matter how courageous you are but when you're down by 50 plays in a half - I don't know if I've experienced that before - not in modern-day rugby league are you going to come close to winning.''
The Warriors were impressive through the first 50 minutes as a double to wing Manu Vatuvei and a try to Ben Henry, who was only included when Lillyman and Taylor were scratched, saw them hold a 16-4 lead early in the second spell.
But when Lee grabbed his first four-pointer in the 53rd minute, things begun to unravel for the Warriors as Campese started to stamp his mark on the contest.
The former New South Wales No 6 has been dogged by knee and groin injuries for the past two years but showed touches of his class in the latter stages of the game after he joined the fray via the interchange bench after half an hour.
Following Lee's first try, Sam Williams crossed just after the hour mark as Jarrod Croker's conversion brought the score back to 16-14 as the Warriors tried to hold on their slender lead.
But when Campese connected with Lee with only a few minutes left the result was settled.
Warriors captain Simon Mannering, who racked up 40 tackles for the visitors, said they were eventually worn down by a relentless Raiders outfit.
"It was just too much on our own line and one set too many.''
Mannering's tackle count was only topped by hooker Nathan Friend who made 61, while Todd Lowrie was also busy as he made 39 tackles.
Young centre Ngani Laumape led the Warriors in metres gained with 137 as he continues to make a bright start to his career.
Canberra Raiders 20 (Edrick Lee 2, Sandor Earl, Sam Williams tries; Jarrod Croker 2 goals) Warriors 16 (Manu Vatuvei 2, Ben Henry tries; Shaun Johnson 2 goals). HT: 4-10