Just saw the replay of this. Matic definitely didnt deserve to be sent off - its not like he punched the guy, he just pushed him to the ground, and with good cause. Should have been a red for the Burnley player and yellow for Matic.
On a semi related note, I find it sad that football has become this pathetic, where pushing an opponent gets you a red card. The referee did a poor job in not taking circumstances into account at all, its like they are trying to take all passion and emotion from the game. I for one would be delighted if more players got a bit angry and confrontational rather than rolling around on the floor like they've had their balls cut off, after any physical contact.