obstruction at first base

Question
I am an assistant coach on my son's little league team and I saw a scary play this evening at first base that has me perplexed.  We play in a league where there are two bases at first, the white one inside the foul line for the fielder and the orange one outside the line for the runner (don't know if this is Little League standard or not). One of our youngest players hit a ground ball to the first baseman, who went to his right to field the ball.  The pitcher ran to cover the base but the first baseman took the play himself, tagging the white bag.  The pitcher arrived at the same time  and ran just in front of the orange bag, knocking over the runner before he reached the base.  The umpire called the runner out and said there was no obstruction because the collision occurred after the first baseman tagged the base.  I was quite upset because I thought both players could have been badly hurt and I insisted that he warn the pitcher about his unsafe play.  Fortunately, both kids were fine, but the question is still nagging at me, "Did the umpire make the right call?"

Answer
Well, I may have missed something here.....First, you stated the the collision happened AFTER the FB tagged first.  Once the out occurs, anything else is just an ugly wreck, but no violation.

However, if the pitcher running to cover actually caused the batter runner to be impeded or slow down, then obstruction should have occurred.  In this situtation, the batter runner is always entitled to the ORANGE & the defense may only contact the WHITE.

But, this cuols possibly be a judgement call so I don't want to say that the ump was incorrect, since I was not there personally.

Thanks, for the question......If this helped please rate me, if not then please advise in return.....

Thanks, Andy