Runner dives over catcher on tag play

[justanotherump]

I really want to find a reason for not calling this runner safe.
My first thought was maybe the umpire thought the runner was avoiding a collision. However, there is no collision avoidance rule for FED. Also, the rule concerning diving over a player is very clear. You can not dive over a player for any reason. this is cleared up in the casebook. If a runner does, he is out.
So my next thought was, maybe the umpire didn't judge the runner's action as a 'dive'. The rule book says that jumping or hurdling is legal if the player is on the ground. So I think we can figure out that a 'dive' is a headfirst leap. Again, the case book says that diving is never legal.
So maybe the umpire judged that the dive was not 'over' the catcher. But watching the video once sets that aside. Then the pictures confirm it.
Finally, maybe the umpire believed that the catcher caused the dive by going into the runner's legs. If you've ever seen this, whether baseball or a running back on the goal line, then you've seen that where this catcher made contact would have caused the runner's upper body to tilt much more to the ground than the lower body. If the catcher caused the contact. This didn't happen.
So I'm left thinking that the umpire maybe had been working more games under MLB rules and forgot this FED rule. Or he didn't know it. Or he just froze under the situation.
This probably wouldn't be a large issue if all the other incidences, right or wrong, hadn't occurred. No matter what, this could be a good life lesson for the kids, as all experiences are. They now know that no one is perfect and when mistakes are made you have to push through..
Thus ends my never ending post.