He of course deleted the tweet rather quickly, but we all know that it only takes one screenshot to make a tweet last forever.
Here's Dufton's apology.
Would like to apologise for that mindless tweet earlier. Very naive mistake on my part. Apologies for any offence caused— Hamish Dufton (@efchamishdufton) December 20, 2014
You can imagine the responses he got, and continues to get on Twitter for that. Remember, always think before you tweet. Especially if you work for a football club.