The most frustrating part of that play at home is that, given where the umpire was lined up, there was no way he could have possibly have had a clean look at the play. He was shielded by Martinez.
He saw that Martinez was blocking the plate, he saw that the throw arrived at the same time as Kinsler, so he called Kinsler out.
But the reality is, there is no way he was in position to be able to make that call.