GLAD DIGGS ISN"T PLAYING SO HE CAN MAKE MORE BUSINESS DECISIONS!
That is one way to look at it. Other observers of that particular Diggs/Kittle play would agree.
Another way would be to re-review the play in slow motion. It could be suggested Diggs was playing the ball, trying to slam his elbow into it, cause a turnover, misjudged his timing and whiffed on connecting with Kittle and the ball. A turnover was sorely needed at that stage of the game. And creating turnovers is a Dan Quinn coaching staple.
All of the above is pure conjecture of course. I posted a slo-mo gif of the play awhile back. I may re-post it later today just so it might get ignored again, haha.