Blind spot is not the issue. the bikie is clearly in the wrong. He speeded and as such he cannot steered his bike to the center of the lane quick enough. Unfortunately the bikie meet his death fate he was in the way of the car which need to filter to the 2nd lane.
This is inaccurate either, because even if you see the rear mirror, it is not necessary reflecting the face of the driver also, it may be just the interior of car or some passengers only. That means driver still can not see you. Anyway, unless you are stalking the driver you don't check another car like that. Just drive normally, and keep safe distance from all others, also give sufficient reaction time to other road users. You can not be a safety angle don't try that and stress out yourself.