That game locked on 3/20th.

That afternoon, OKC announced Durant was out indef.
Brandon knight ain't play since March 9th

Those were 2 obvious drops. Now you only got 10 bodies including

Tobias Harris who got injured on March 17th
James Johnson who don't play consistent minutes
Klay thompson who had got injured on the 17th and supposed to miss up to 10 days

The Shved and Whiteside injuries, there was nothing you could do about it. The rest was forseeable.

Then again, projections got you losing by over a hunnid so maybe you were right. :-)