The lead investigator was seeking to clarify earlier comments by police that suggested some of the driver's actions were deliberate.
Band members Kris Leonard, River Reeves, Jack Dakin and Tomas Lowe died, along with manager Craig Tarry, 33, near Stockholm on 13 February.
Lars Berglund said the driver's "only intention was to avoid a crash".
Witnesses reported seeing the car going though red lights and barriers before the Warrington band's car plunged 80ft (24m) into a canal off a bridge, the middle section of which was raised.
Mr Berglund told Mirror reporter Rhian Lubin: "I have not suggested that [the driver] was doing this in order to kill himself or the band. I said he was making a move from the right lane to the left lane and that was not accidental.
"We can see the brake lights. His intention was to stop the car. But maybe his speed was too high and it was too late."
Earlier, a Stockholm police spokesman said: "It looks like he [the driver] tried to drive past red lights, barriers.
"All the witnesses thought it looked like he was trying to drive past... there weren't supposed to be cars on the left.
'It is a possibility he deliberately crashed the car, but he may have misunderstood the signs.
"[It is] still subject to investigation and we are still waiting for results of technical investigation too."
Police have previously confirmed the driver, who has not been identified, had no traces of alcohol or drugs and said it would have been very difficult to pass two lines of parked cars if he was asleep.
The car, carrying the four members of the band and their manager, was recovered from the canal under the E4 highway bridge in Sodertalje, Sweden.
In the week after the accident, the band reached number one in the iTunes chart following a social media campaign backed by Oasis singer Liam Gallagher and Tim Burgess from The Charlatans.
A concert in the band's memory at Warrington's Parr Hall on 2 April has now sold out.
The gig, which will feature friends and bands they have played with, will be hosted in their Warrington hometown by BBC Radio 1 DJ Phil Taggart.

The 29-year-old England international has not made a final decision, but is understood to favour extending his time at the King Power Stadium.
Arsenal made a reported bid of £20m for Vardy, activating a release clause in his contract and offering him a deal reported to be worth £120,000 a week.
Leicester responded with an offer said to be worth £100,000.
Arsenal do not plan to improve their offer and are thought to be pursuing alternative options.
Vardy, who joined Leicester from non-league Fleetwood Town for £1m in 2012, signed a three-year deal in February, and the Foxes' new offer would extend that into a fourth year.
Arsenal's offer was a three-year contract with the option of a fourth.
Vardy, whose tally of 24 league goals last season was bettered only by Tottenham's Harry Kane, is currently with the England squad at Euro 2016.
The Gunners asked Vardy to give them an answer before he flew to France, but he wanted to focus on the competition.
Swedish police say they do not believe the Viola Beach crash driver "intended to kill himself or the band".
[NEXT_CONCEPT]
Leicester striker Jamie Vardy is set to reject an offer to join Arsenal and stay with the Premier League champions.