The initial arrest has nothing to do with the current situation. It may be the cause of it, but it is not a factor in whether he should be arrested or not.
Regardless of whether it's "moral" (humanity) to do the whistle-blowing, nevertheless, he still committed treason. If he managed to get out of the country, good for him, but he did not, was arrested and put into jail.
In most nations, treason is punishable by execution. Even in Canada, where capital punishment is abolished, the law does not explicitly rule out capital punishment for high treason (although it is exceedingly unlikely to occur). It is the only crime in Canada you could be executed for.
He was put into jail for life. Whether or not this "coerced" him to sign the contract for his freedom, he could have been left to rot in there. He opted to sign and is obligated to follow the contract terms.
He was not only doing something illegal in that interview, he was also doing something MONUMENTALLY STUPID.
Furthermore, since he's not doing any whistle-blowing this time, there isn't even a moral excuse to do so. He should've just gone and lived quietly.