I came across this sentence in my textbook (上級へのとびら):
As far as I'm concerned, 終わる is an intransitive verb and as such, it can't be used with the particle を, but with が. The transitive counterpart is the verb 終える.
What is the reason for using 終わる as a transitive verb in the sentence above? If this is a legitimate use (which I assume it is, as the example is taken from a textbook), is there any difference between 終わる (transitive) and 終える？