Here is the full explanation on the "obstruction" call against Felix Hernandez in the fourth inning:
Jerry Layne (HP Umpire and Crew Chief) and Hunter Wendelstedt (3B Umpire):
Q: Can you comment on the play?
Layne: Any time you have an obstruction before first base, you have a rule.
Wendelstedt: It's 7.06a
Layne: Any time the runner is obstructed before first base, the ball is dead. He's awarded first base, and any runner that could be forced is awarded [his base]. That's why [Wells] was given second base. What had happened was when they went to field the ball, the pitcher and the first baseman were going toward the bag. There was a second there when neither one of them knew who was going to cover, in my opinion. I don't know that, but that's what it looked like. But the person that didn't receive the ball, which was the pitcher, obstructed the runner going to first base. Per that rule, any time it happens before first base, the ball is dead. That clarifies it. Eric [Wedge] said it didn't happen before first base, and that's what the discussion was about.
Q: Did it make a difference that the runner was out by two steps?
Wendelstedt: We have a clarification in the baseball rules interpretation manual. Only one fielder can be in the act of fielding the ball. Now that fielder [in this case] was the first baseman. So that’s where the obstruction came in because there were multiple fielders fielding the [throw]. Now there's a couple of different kinds of obstruction. But on the type of play like this, which was a ground ball, it doesn't matter if the runner is 89 feet away when he gets obstructed or if he’s one inch away. If he is obstructed before first base, the ball is dead and he is awarded first base.
Layne: As soon as that happens, the play is dead.