Interference?

[NCASAUmp]

I say this is a very HTBT play, but I think that it is possible that the ruling in the OP is correct. If a runner blocks the fielder's view of the ball, that, to me is INT as it impedes the fielder to field the ball and execute a play.

Now, we see these kinds of plays happen a lot, and a lot of it will depend on the judgment of the umpire. There's no way we can remove judgment from all INT calls, and the OP is no exception.

However, as I've said in past posts, for me to call INT on a play, I'd have to have something concrete that I can see and use as my justification. I'm not sure it's quite there in the OP, but I can see where MGKBLUE might be coming from.