The substance - which Froome says is used to help manage his asthma - is permitted without the use of a therapeutic use exemption but only within certain doses.
Team Sky said Froome was only 19% over the limit - not double as has been previously reported - when the adverse test was adjusted to take account of dehydration.
They also claim 20 other tests conducted on Froome during his victory at last year's Vuelta a Espana did not need any "further explanation".
"The same individual can exhibit significant variations in test results taken over multiple days while using exactly the same amount of salbutamol," Brailsford said.
"This means that the level of salbutamol in a single urine sample, alone, is not a reliable indicator of the amount inhaled".
Decision based 'on expert opinions'
A UCI statement says that "on 28 June 2018, Wada informed the UCI it would accept, based on the specific facts of the case, that Mr Froome's sample results do not constitute an AAF (adverse analytical finding)" and "in light of Wada's unparalleled access to information and authorship of of the salbutamol regime, the UCI has decided to close proceedings against Mr Froome".
The statement added: "While the UCI would have obviously preferred the proceedings to have been finalised earlier in the season, it had to ensure that Mr Froome had a fair process.
"The UCI understands that there will be significant discussion of this decision, but wishes to reassure all that its decision is based on expert opinions, Wada's advice, and a full assessment of the facts of the case."
Of course, none of us should have know anything about this. However, the Guardian published a story by journalists Sean Ingle and Martha Kelner. Totalling over 1,500 words, the essentials were summed up by the 11-word headline: Chris Froome fights to save career after failed drugs test result.
Where did the journalists get their information?
Team Sky’s star and Bradley Wiggins were part a group of 25 athletes who had their data stolen from the World Anti-Doping Agency (WADA) and published by Russian hackers known as ‘Fancy Bears’. It was the second such leak in a week involving athletes from the 2016 Rio de Janeiro Olympics.
Footnote: Fancy Bears are an anonymous cyber espionage group responsible for leaking confidential information from the worlds of politics and sport.
Their earliest work included hacking Georgia's government ministries before the Russian army invaded the country in 2008.
Since then, Fancy Bears have targeted the White House and the CIA and were responsible for the email hack of the Democratic National Committee which is thought to have badly damaged Hillary Clinton’s campaign for the presidency.
The group has infiltrated computer systems of several foreign governments and were accused of trying to disrupt the 2017 General Election. It is also suspected that they had involvement in the BREXIT referendum.
Many believe that they are working on behalf of the Russian Government who, it is claimed, fund them.