It's more about firing back at what CyclistAbi has accused everybody who doesn't agree with their contention that the UCI bears sole responsibility and airbags are the solution to all woes of.Did you actually ready the whole article? They literally say:
Not all the blame can be put at the riders.
Also I would include "speed of the péloton" in "rider behaviour" more widely, personally, I'm assuming they're meaning things like not looking where they're going, swerving, poor sprint discipline and either reckless or poor bike handling in corners as "rider behaviour". Typically my perception is that a thing like speed of the péloton does not in and of itself cause a crash, but it does exacerbate the impact that that crash has, by meaning the likelihood of injuries is increased, either by the severity of injuries being worse, or the number of riders involved is higher because reaction times are lower, thus increasing the likelihood of somebody emerging injured from the incident.