According to your article:
Israeli police have released a Jewish extremist that was held in administrative detention for almost 10 months on suspicion of playing a leading role in a terrorist group targeting Palestinians.
Far-right activist Meir Ettinger was released without being charged on Wednesday, although he is still under heavy restrictions, local media reported.
He was initially taken into custody in August of last year for allegedly taking part in an arson attack in the West Bank that killed an 18-month-old boy when he and his parents were burnt alive.
Several extremists were arrested at the time, two of which were eventually charged with the arson.
This seems reasonable. He was not charged with anything, he was held in administrative detention (which is what is more frequently done with Palestinians) and he is still under heavy restrictions.
The thing is - if there is a lack of evidence to charge him, then he SHOULD be released.