Shackled?
He made that tweet himself. Chose exactly what that character limit would send out into the internet. What crux of the issue he would want encapsulated in a soundbyte. Then surely thought it through - no matter what his 'apology' would have you believe - and clicked send.
He done a pretty **** job of it. He might be a gifted geneticist but when it comes to Twitter he's rubbing shoulders with Joey Barton and the Iron Sheik.