Mooredog,
If you ask me that's a pretty serious infraction. there's a new rule out there that starts like this.......poker is a game of observation......(I think this statement fits a situation like this better than the rule it was intended for).......so pay attention. Based on the limit of the game being played, we should assume that the players are competent enough to know when it is their turn to bet. After a warning, a second offense could draw a one button orbit, or more, depending on the number of players. While I was writing this post, Dave Lamb wrote that he would give a one hand penalty along with the warning. I like that even better than a warning alone.