Here's the Story
Here's my Opinion
The language the father used and the actions he took were all wrong but understandable. When it comes down to it; it is the responsibility of the parents to protect their child and he felt he had to do what he did in order to protect her. But I also think that if the father reported the incident to the school and the school did not act quickly or even at all that they should be held responsible for the child's safety as well. In this case I believe there is such a thing as doing the right and the wrong thing.
Update
The father has apologized for his approach to the situation during a news conference you can read about it here http://www.cnn.com/2010/CRIME/09/21/florida.father.bus/
Psalm 20:1
May the LORD answer you when you are in distress; may the name of the God of Jacob protect you.