Exactly, first the principal abuses his/her position, then he/she committed theft. So this is not to be taken lightly. I don't know what going on the mind of the principal, but it boils down to one reason alone, to make money and be greedy. Not good for someone who has a high position specially being the top head of a school.
I guess the principal should be also be jailed for this one because this is theft. And we all know that China government is really tough law regarding criminals. There were even reports prior of persons being caught stealing electricity for mining and receiving 3-5 years jail term.