Only seen couple of times but as an ex kicker would have been cursing the ref. I do not think the kicker moved his feet so opponents cannot charge down all kickers these days have twitches etc. Think the ref got this wrong.
Start of the kicking motion is fair game, he made a movement and then they started the charge down
Similar to Stringer on JOC where JOC raised his arm (didn't move towards the ball) but because it was the start of his kicking motion Stringer was allowed to charge down