Owen and Teddy committed a crime related to Owens study on giving life-ending drugs to veterans suffering from pulmonary fibrosis. Owen stole life-ending drugs to give to veterans asking for them, and Teddy decided to cover for him and even questioned John, the husband of a veteran from Utah, who wanted the drugs to let her wife die peacefully, or he would’ve turned in Owen to the authorities. Teddy knew that when the truth about what Owen was doing came to light, he might have risked prison. In the Greys Anatomy season 18 ending, Teddy and Owen ran away from Seattle with Allison and Leo, knowing that Bailey would have had to turn Owen in. The crime committed by Owen was that he secretly gave a patient medication that would allow him to pass away. Owen thought he was making a deathbed confession to Cormac, but it turns out, all three of them actually survived the crash. That left Cormac in the difficult position of knowing about Owen’s crime, so he decided to leave Seattle and return to Ireland with his family.