Scrum-half McCarthy scored the first of six tries as Ireland ran out 40-0 winners againstScotland to finish in third spot whilst England retained the Justin Bridou Trophy with a 27-22 victory over France.
And after a narrow 23-18 defeat to hosts France in the semi-finals, McCarthy was pleased his side responded in such fashion and insists they can leave with their heads held high.
"I am really proud of the lads and we were really hoping to get win because we were very disappointed after the French defeat," said McCarthy.
"I just think we stood up to them really well at the start and we got points on the board early and they found it difficult to get back into the game once we did that.
"We [were all] a bit disappointed that we [weren't] playing in the final but it's obviously nice to get that really good win so we are all pretty happy."