The Lindrick Golf Club member finished level par in the fourth round on Sunday in the men’s event that saw him tied half-way down the leaderboard.
And Willett wasn’t pulling any punches in his own assessment of how the week had gone in Brazil.
He said: “I’ve been relatively poor all week, things haven’t gone my way and I’ve not done anything special. It’s disappointing to finish mid-pack in a field that isn’t fantastic.
“There are low scores possible. If you get a little bit wayward then you get in the bunker and it’s a toss-up if you’re going to plug or not. Every time I was in the bunker I plugged.
“The golf course in itself is a pretty good setup. It’ll be interesting to see how the women get on next week with the tee positions.”
Great Britain team-mate Justin Rose won the gold over Henrik Stenson and became golf’s first Olympic champion since 1904.
And the 28-year-old was pleased he made the journey when some of the other top golfers from around the world had decided not to play in golf’s return to the Olympic Games.
“It’s been a good experience overall,” said Willett. “Staying in the village and mixing with all the other athletes; chatting to them and seeing how they go about their day.
“It’s opened our eyes a little bit, to see how they train and hopefully we’ll take little bits back for ourselves.
“Anybody who has come here and stayed in the village will have had a great week, you won’t find anyone who’s not.
“The entire event has been fantastic.
“There were a lot of concerns before we came but everyone who’s made the effort to come down, and all the spectators have had a good time.”
Meanwhile, Willett and Worksop’s Lee Westwood will represent England in the World Cup of Golf at Kingston Heath in Melbourne.
As the highest-ranked English player to commit to the two-man team event from November 23-27, Willett had the right to choose his partner and opted for the man who finished second behind him at Augusta in April.
“It’s always great to represent your country,” said Willett. “You don’t get the chance to do it too often so I’m excited about playing the World Cup.
“I was at Royal Melbourne in 2013 and although I didn’t play as well as I would’ve liked, it was a cracking course and I’ve heard Kingston Heath is just as good.
“It’s a different format this time so I’m really looking forward to playing with Westy. He’s played in nine Ryder Cups and has unbelievable experience of foursomes and fourballs, so I couldn’t have picked a better partner.”
Westwood, 43, has surprisingly never played in the World Cup before.
He added: “Over the past couple of years Danny has shown what he’s capable of and I’ve got no doubt he’s going to prove a great partner, so I’m looking forward to pairing up with him.
“I’ve always enjoyed team golf. It’s an exciting format and it adds to the occasion when you’re playing for your country, so hopefully we can bring the trophy home with us.”