and i have been driving for 42 years. i look over my shoulder to check my blind spot multiple times a day, every day since i got my drivers license.
i have never rear ended anyone.

so the concept that looking over the shoulder to check your blind spot will make you rear end someone is equally absurd.

in my opinion trying to check your blind spot by looking in the mirrors takes longer and is much more hazardous than just turning your head around to check your blind spot.

as the link i posted earlier. the Wisconsin, and probably every other state in the USA, DMV DRIVER TRAINING MANUAL RECOMMENDS looking over your shoulder to check your blind spot before changing lanes. it has been that way since i got my drivers license and probably been that way MUCH MUCH longer than that.