It isn't Pat Shurmur.
This is easily established by looking at the account's front page. Fake Pat Shumur has two tweets, but it says it has 14; and while the first tweet is from Friday saying "trying this out" the account was created in 2012; and it has over 31,200 followers in less than two days, which is unattainable unless you're a massive celebrity or you pay for fake followers.
Clearly this is someone else who has deleted all the previous tweets to make the account appear to be new. A simple look at the account's favorites reveals the previous user (and amusingly this NSFW tweet), who has undergone various twitter handles: @vu_proxy, @proxanometry and @timmyjernigan. It is not Timmy Jernigan of the Baltimore Ravens and snowman making fame, the actual Timmy Jernigan is @TJernigan8. The @timmyjernigan account shows up as suspended. The former handles can be confirmed by going to any of the favorited tweets that are in reply to any of those accounts and, at least on iPad and iPhone, seeing that while the original tweet was deleted, it still, extremely briefly (the "in reply to" goes away within a second), shows that it was in response to the @vu_proxy/@proxanometry/@timmyjernigan account.
So, who is this person? A Google search shows that @vu_proxy/@proxanometry claims to be a "professional Call of Duty player", you can check out his videos here. Judging by the twitter lists this person is a part of, either goes to Baylor or is a big Baylor fan. A deeper Twitter search shows that he's possibly also impersonated others before Jernigan and Shurmur:
@ImBigRig @Vu_ProXy seriously though I'm real and your not but you have basically all my followers that should be following me. I should sue— Cody B (@_TheRealCodyB) November 8, 2013
Whoever he is though, it doesn't really matter. All that does is that @PatShumurOC isn't Pat Shurmur. Which is what makes this so noteworthy: of all the people to fake being, it's Pat Shurmur? Nothing against the man, but he's so uninteresting that it's notable. Chip Kelly wows the media, Billy Davis is an impressive interview, Jerry Azzinaro has "more violence". Pat Shurmur... has an article written about him titled "Who is Pat Shurmur and What Does He Do" and after reading it we still don't know what he does. Part of that is on the author, Marcus Hayes, but Shurmur doesn't help any. Why pick Pat Shurmur, other than to see how many people will blindly follow the account? That's probably reason enough. But it's no reason to follow him. Or perhaps he is a Cowboys fan.
UPDATE 12/7 2:30pm
He's moved on to impersonating Broncos safety Rahim Moore.
This is just sad.