He pleaded guilty to the charges, admitting that he had sex last year with the victim, who was 16 years old at the time, after the pair smoked high-potency marijuana known as "dabs."
A main argument during sentencing was whether Bruder deliberately gave the victim drugs in order to take advantage of her.
The deputy district attorney had argued that Bruder provided his sister with drugs after she repeatedly denied his sexual advances, and waited until she reached a point of no longer recognizing that he was her brother.
But Bruder's defense attorney claimed the incident was a result of bad decisions the siblings made together while smoking "dabs." He pointed out that the victim took off her own clothes and was not unconscious, adding that there was no sufficient evidence for a jury to convict Bruder.
Follett said he was swayed by 18 letters of support from Bruder's family, adding that he didn't believe the young man had gotten off "scot-free" or that he posed a high risk of committing a similar offense in the future.
But the district attorney condemned the decision, comparing the case with the story of a former Stanford swimmer Brock Turner who raped an unconscious woman outside a fraternity party but only served three months in prison.
"In a lot of ways, this case is more egregious than Brock Turner," he said in a written statement. "This defendant took advantage of a position of trust."
After the Turner controversy, the law was changed to deny probation in such cases, but Bruder's case predated the law change, so he was not affected by it legally.
Bruder was taken into custody in the courtroom to be transferred to county jail. He must register as a convicted sex offender for life, complete sex offender and drug treatment therapy and perform 140 hours of community service.
Judge Follett is facing criticism after it was highlighted it is not the first time he has gone lighter than the prosecution asked in a sex-related case. In a prior case, a former Del Norte High School coach received "a lighter than recommended sentence" from the judge after he was found guilty on multiple counts of an inappropriate relationship with a minor.