The World Cup winners scraped to a 23-13 victory over Philippe Saint-Andre's side at Eden Park on Saturday, courtesy of two counter-attacking tries late in the first half.
The home side were without regular captain Richie McCaw, who is on a sabbatical from top-flight rugby until the end of the month, and Hansen gave openside flanker Sam Cane the nod to cement his place as McCaw's successor in the side.
But Cane, who scored one of the All Blacks tries, and the other forwards found the French tough to combat at the breakdown with Fulgence Ouedraogo, Thierry Dusautoir, Yannick Nyanga and Sebastien Vahaamahina particularly adept at disrupting that area of the game.
"Yeah it didn't flow and it wasn't a hundy (hundred percent) but the opportunities, if we modify a few things and get rid of the unavoidable errors like turning the ball over unnecessarily, then we will have something to really build on," Hansen told reporters at the team's central Auckland hotel on Sunday.
"Some of it was ball security, some of it was the ball carriers going in and turning it over, or going to ground too early, some of it was not enough numbers.
"We can fix all of those."
Fixing those problems was about attention to detail and proper execution, Hansen said. They will work on that in the buildup to the second match in Christchurch on June 15.
The team had no injury issues from Saturday's game, though first-choice lock Sam Whitelock (broken hand) was unlikely to be available, he said. Loosehead prop Tony Woodcock (hamstring, nose) and scrumhalf Piri Weepu (concussion) are likely to be considered for selection.
Those returning from injury aside, Hansen expected to have some continuity of selection for next week's match.
Even if the All Blacks clinch the series in Christchurch there is no guarantee Hansen will make changes in New Plymouth for the final match on June 22 because he has already taken a few selection risks.
Hansen gave the inexperienced Dane Coles, Wyatt Crockett, Cane, Aaron Cruden and Ben Smith starting roles at Eden Park as he looks to develop the squad and build to the 2015 World Cup.
"We did experiment in this one," he said.
"Last year it was about getting some credibility for the players and coaching staff. This year is about growing the team and the leadership group and we will be taking some risks.
"I have said we took a few last week, some may have been forced by injury but c'est la vie.
"We could have pushed people out there but we didn't, we trusted the people we have in the squad.
"Over this three match series a lot of people will get an opportunity. Some won't because they may not be quite ready but those that are, will."