The Manchester United defender believes the club's Premier League title win means that his teammate made the correct decision leaving the Emirates for Old Trafford.
Van Persie spent eight years with the Gunners before moving to Old Trafford last August for £22.5 million [€26.8m], and the Dutchman has shown his undeniable quality by netting 25 league goals, a record for the most goals in a debut campaign for the club, to lead the Red Devils to their 20th league title.
The 29-year-old scored against his former club in their 1-1 draw at the Emirates on Sunday and chose not to celebrate, but that didn't deter the Arsenal fans from taunting him throughout the match, something which Evra cannot understand.
"I still don't understand why the fans boo him," he told reporters. "I am disappointed that the fans have quickly forgotten what he did for the club. I think he felt it as well.
"He hasn't made the wrong choice. It was a long time that he didn't win the league title [at Arsenal]. He has come to Manchester United and won it."
Sunday's strike means Van Persie is now just one short of 30 goals in all competitions this season, and boss Sir Alex Ferguson believes hitting that milestone will justify the money Manchester United had to part with to bring him to Old Trafford.
"He has the chance to reach 30," the Scot told reporters. "If he does that, it justifies all our faith and hope in him."