When you say now, do you mean half way through the season or from the start of the season? Surly they don't change the rule half way through the season.
If from the start of the season and the three Red's are 'exceptions' to the rule then is it fair to assume we have had say 100 or so these sort of headbutts so far this season to make yellow the norm rule. Surly 3 Red's and say 5 yellows doesn't make the Red's 'exception' to the rule.
Hope you can see the logic I am trying to apply
Edit: the cynical part of me says the reason this was not charged retro was the FA bottom line, sponsors etc.
