The paradox of Boris Johnson, not for the first time, unfairly blaming poor cycling for a spate of deaths which could more realistically be tied to the patchy bike infrastructure he oversaw, is that London's mayor is otherwise arguably the best cycling champion in British politics.

He does use a battered hybrid bike as his habitual London transport, not as a Cameron-style photo opportunity. Last week when Johnson opened a revamped section of the so-called cycle superhighway, in the pouring rain, the press contingent arrived in cabs or by tube. The mayor and his "cycling tsar", Andrew Gilligan, turned up, dripping wet, on two wheels.

Also, for all the very justified worries about whether the "superhighways" – for the most part slim gullies of blue paint which London's motorised transport long ago learned to ignore – Johnson has also ushered in possibly the boldest plans to boost cycling ever seen in contemporary Britain.

In May, he and Gilligan unveiled their long-term vision for bikes in the capital, a near-£1bn plan including a hugely ambitious and mainly segregated east-west cycle highway. In a move as much symbolic as practical, part of its 15-mile route would involve taking a lane from the Westway, the elevated carriageway from west to central London which epitomised the car-dominant planning of the 1960s. Last week came plans for a similar north-south route.

Such schemes, along with plans for a system of bike-friendly "mini Hollands" in outer suburbs have seen Johnson and Gilligan win some praise even from regular critics like the London Cycling Campaign.

And yet, no stranger himself to the occasional disregard for the law on his bike, Johnson has something of a habit for unfairly blaming those on two wheels for accidents.

In May last year Johnson cited a statistic at one of his mayor's question time sessions: 62% of accidents in which a cyclist was killed or seriously hurt in London, he proclaimed, were found to have been connected to cyclist law-breaking. Cycle groups scratched their heads at the figure and asked for a source. Months passed, with the mayor's office saying the reference was "being researched".

Eventually, Johnson came clean: he had been told the figure by a member of the public at a meeting and trotted it out without checking. Transport for London then came up with the real proportion of cycling accidents found to have been due to cyclist law-breaking: 6%.

On Thursday, faced with five cyclists killed around the capital in nine days, Johnson decided not just to express his condolences and promise to see what lessons can be learned from the new tragedies but talk in an interview about light-jumping and other "very risky" behaviour by cyclists.

Aside from the obvious crassness of such speculation when friends and relatives are still in the beginning stage of mourning, Johnson's theories are not borne out by the statistics. Aside from the TfL figures, a national study for the Department for Transport in 2009 showed that where cyclists were seriously injured in collisions with other road users police said that the rider disobeying a stop sign or traffic light was a likely contributing factor in just 2% of cases.

Red light jumping among cyclists certainly exists in London, and there's a good argument that it's anti-social and even intimidating for more vulnerable pedestrians. But, counterintuitive as it seems, such behaviour doesn't seem to be completely perilous.

If Johnson really wanted to distract attention from the apparent dangers of cycle superhighway 2, on or by which three cyclists have died in less than 10 days, he could have picked another, more relevant target: lorries.

Earlier this year a TfL study warned that construction lorries rushing to make unrealistic deadlines at building sites were a particular danger for cyclists, and urged the industry to take action.

This is an area where even Johnson cannot doubt the statistics: in recent years around 50% of all cyclist deaths in the capital have involved lorries, often a truck turning left across a cyclist. And what proportion of London's traffic is made up of lorries? About 5%.