Depends on what you mean by "accident," Lew.
If you mean the occurrence was unintended, then yes, I agree. The motorcyclists certainly wasn't out there to hurt people.
But the word "accident" is sometimes used to support the idea that there's no legal responsibility (read: liability) for the action. That shouldn't be the case here. For all the reasons that have been presented, the cycle rider did not accomplish what a prudent and reasonably competent rider should have done: avoiding a collision with the bicyclists, who were proceeding legally in clear view.
OK. Back to retirement now.