Linford Christie never broke a world record (to my knowledge).
All sprinters “side-step” to some extent in the early strides from the blocks. It is a case of delivering power to overcome inertia from the set to first step, also a case of “making space” to drive the pelvis through, also a process of making time to coordinate arms and legs in this early acceleration phase. I cannot think of a sub-10 100m runner who has not side-stepped. But you need to straighten it up sooner rather than later. However it is a completely natural movement and process which shouldn’t be over-ridden because the textbook says the shortest distance between two points is a straight line. Just my opinion.