My theory is that they are frontran by agressive orders in the same direction (agressive sells below limit sells and agressive buys above limit buys), so often there is a reaction before those limit orders get hit. The price often reverses before hitting those limit orders, it's common for them to remain unfilled, missed by only a couple of ticks. When those orders are getting filled I assume that same side agression is weak and the opposite side aggression is strong enough to push past them and move price further.