Just watched the "highlites" again, absolutely abysmal refereeing for the winning MK goal. Very debateable free kick which could have been awarded to us, not content with penalising us for a 50/50 the ref allows MK to take the kick a good 5Mts away from where the "Offence" took place and the ball is 100% still moving. Apart from that there was nothing wrong with it !
It was a foul, Marshall pulled the player back. Taking a quick free kick 'in the vicinity' is acceptable unless the official says otherwise beforehand, especially when it's not for a direct shot on goal. The 'moving ball' is debatable because the player puts his hand on top of the ball before he kicks it.
To be honest, having watched it, I'd be looking more to blame the experienced player who chose to argue with the official, rather than prevent the free kick being taken quickly. Especially that late in the game and in such an attacking position.