An FM music station using an online clock is rare. The streaming servers of most music stations are set up to intercept certain spots by cart number in the computer and replace them on the streaming box. Others will look for a subaudible tone in spots that need to be covered, but I'm not aware of any live and/or locally automated stations running off of a timer. A few years ago, I worked at a station that ran satellite programming in the off hours and would replace ads that ran after the ID ran between certain times.
I suppose it's possible that CBS uses a clock for 1580 and accidentally put it on 94.7's stream, but, depending on when during the song the spot fires, it seems more likely that a sec tone was misplaced.