"Rawana's Bow (Rawana ge dunne)" joke

A school inspector went to a school for his annual inspection to check the educational quality and standard of the grade 9 students. With out the presence of teacher he took over the class and started to check the knowledge of history. He address Nimal who was seated in the front row " Nimal, tell me who broke the bow of Rawana? (Nimal kiyannna Rawana ge dunnna kaduwe kawda kiyala").
Nimal replied " Sir, I never broke Rawana’s bow, somebody must have told a lie to you"
School inspector was frustrated to see the poor standard and the knowledge of history of these students. As an experienced educationist, he thought the students should not be blamed but the teacher. So he called the class teacher and blamed him " look here Mr Silva, I am very disappointed about some of the answers given by your students". Mr Silva, the class teacher very politely asked, can you explain me further?
The inspector explained " I have asked one of your students who broke Rawana’s bow? student said that he never broke Rawana’s bow". Teacher was keen to know who gave this answer. Inspector said that the answer was given by Nimal who was seated in the front row.
Then the teacher said, " I know Nimal very well, he is not that type of person who will break somebody’s bow. If he said he didn’t break, believe him, I am sure he wouldn’t have done that"
Inspector thought no use talking anymore with this guy. Not only the students but the teacher also have no knowledge about history. He decided to report this matter to the school Principal.
He went to the principal and said " I am very dissatisfied about the knowledge and standard of the grade 9 students in your school. Anyway, I can understand this, but what I can’t tolerate is even the class teacher do not have a sufficient knowledge about what he supposed to teach." Then he explained to the principal about the incident. He described about his question, how the student answered, when he complained how the teacher responded."
Principal devotedly listened to the whole story and said " Well I have no knowledge about each of the students in this school, class teachers are the best persons to comment on students, If the teacher also confirmed that this fellow wouldn’t have done that, so you have to believe him"
The inspector was really disappointed. Now he is worried about the knowledge and standard not only the students and the teacher but the principal also. He thought pointless talking to these guys, better I take this matter up with the Regional Director of Education.
He went to the Regional Director of Education, explain all what happened from the time he asked the question from the student up to the reply given by the principal. Inspector said it appears to be something drastically wrong with the whole school, starting from the students, teacher and up to the principal.. He express his concern not only lack of knowledge on the history but the lack of commonsense up to the level of principal of the school.
Regional Director carefully listened to this complain and finally replied.
"Well, your story look very complicated to me. Don’t worry about trying to find out who broke Rawana’s bow. If you bring both pieces of the bow, and three quotations for a new bow, I will issue a purchase order to buy a new one."