Roos agreed the Blues' nine-goals-to-nil last quarter was uncharacteristic for his players after they got themselves back in the contest in the third quarter.
"I'd say it would have to be one of the most disappointing games in the last seven years, no question," he said after 61-point loss at Docklands.
"Generally, we really fight hard and can swing the momentum back, and probably did in the third quarter.
"In the last quarter, we dropped off significantly and they were able to run."
The Swans will remain in Melbourne on Saturday night to celebrate their Hall of Fame evening at Crown Palladium.
Roos said the game's result was a sad way to begin what should have been a celebration of the club's success this decade.
"It is disappointing you've got to front up to the Hall of Fame after a performance like that," he said.
"I'm sure the majority of the guys there would be more talking about the 2005 premiership than today's game.
"Certainly you'd like to go into a function on a high. It's a big night for the footy club so it's disappointing from that point of view."
Roos said he wasn't surprised the Blues were able to halt their nine-year losing streak to the Swans on Saturday, given their recruiting in recent years.
"I think the expectation of everyone going into the season was that Carlton was going to play in the finals," he said.
"The nature of the draft is, if you're down there for so long … you can now see the talent level [Carlton] has now been able to assemble.
"I didn't see anything today to change my mind. I had them in the eight at the start of the year.
"It's always hard to compare other teams, but they're a genuine top-eight team because they've assembled that genuine top-eight talent. Most teams that have that midfield talent, you would expect to play in the finals.
"They're on course to do what they set out to do at the start of the year."
